ISRO Fans Club

Floating Asteroid Belt colony by 2026 - A Proposal

noreply@blogger.com (Sagnik Chatterjee) — Mon, 25 Jan 2021 13:51:00 +0000

Artist's impression of an interstellar colony. (Credit: The Sun)

The main belt asteroids can possibly be inhabited by 2026. Humans could live in this 'rocky' region between the red planet, Mars and the gas giant, Jupiter, in gigantic orbs!

Dr. Pekka Janhunen, an astrophysicist at the Finnish Meteorological Institute in Helsinki, put forward his idea of an unusual megacity between Mars and Jupiter. He took the model of Ceres, the largest known asteroid; also a dwarf planet, to depict how an interstellar colony might look like.

Ceres. (Credit: Space.com)

FYI, Ceres is 520 million kilometers from Earth. Pretty distant.

In the words of Dr. Janhunen, "The motivation is to have a settlement with artificial gravity that allows growth beyond Earth’s living area." The disc-shaped colony that he has thought of, will be comprised of thousands of cylindrical structures, each with the capacity of sustaining 50,000 people, all of which will be connected using strong magnets.

But, won't we float? The megastructure with it's cylindrical components will slowly rotate thereby creating artificial gravity. For reference, the Starship Avalon from the sci-fi movie Passengers or the Cooper Station from Interstellar.

"Lifting the materials from Ceres is energetically cheap compared to processing them into habitats, if a space elevator is used because Ceres has low gravity and rotates relatively fast, the space elevator is feasible", Dr. Janhunen wrote.

Artist's impression of a space elevator

Ceres has got an advantage over Mars, Ceres' atmosphere is Nitrogen-rich whereas that of Mars is carbon-dioxide rich, as a matter of fact, Ceres dwellers can easily create Earth-like surroundings as compared to the humans settling on the harsh environment of Mars.

But Ceres is prone to space radiation and collisions of all sorts, this issue can be settled by installing giant cylindrical mirrors those would protect the inhabitants from the space hazards, Dr. Janhunen said.

The low gravity on Moon and Mars can lead to several bone-related disorders especially in children whose muscles need gravity assist for proper growth, writes Dr. Janhunen, moreover the surface areas are relatively less on Moon and Mars, as compared to that of Earth, which in turn will affect the financial economy. Hence, Ceres is the destination.

The proposed Ceres mega-satellite:

(Credit: Dr. Pekka Janhunen)

A number of spinning habitats are attached to both sides of the disk, denoted by dots. To gather sunlight, two 45° inclined mirrors are added. The mega-satellite is in microgravity so the mirrors and their support structures are lightweight. Nearly all mass is in the habitats. Thus the mass distribution can be made circularly symmetric so that the tidal torque is zero.

To keep the mass distribution symmetric, one can transfer water or other ballast fluid between tanks. Any remaining tidal torque must be treated by

active attitude control, for example by using the spinning habitats as reaction wheels. Small changes in the level of artificial gravity are not likely to

be problematic for the inhabitants. A propulsive attitude control system can exist as a backup. Read more from Dr. Janhunen's article here.

(Note: There is no intent of content infringement in this article, Dr. Pekka Janhunen reserves the right to her work.)

BOOK REVIEW: Handbook of Space Security: Policies, Applications and Programs

noreply@blogger.com (Ashmita Deb) — Sun, 24 Jan 2021 10:49:00 +0000

Book Review: educational

Title- Handbook of Space Security: Policies, Applications and Programs
Author- 120 authors from 30 countries
Editors - Kai-Uwe Schrogl, Maarten Adriaensen, Peter L. Hays, Ntorina Antoni, Christina Giannopapa, Jana Robinson
Format- Paperback, eBook
Link- Amazon, Springer
Pages- 1587
Publisher- Springer Nature Switzerland AG 2020
Date- 2020
Retail Price- 623,99 €
ISBN- 978-3-030-23209-2 , 978-3-030-23210-8 (eBook), 978-3-030-23211-5 (print and electronic bundle)
https://doi.org/10.1007/978-3-030-23210-8

"Space security is a key factor for survival"

Do you want to explore the security aspects related to space from various regions perspective? If yes, then this is the perfect book to dive in. Let's look at a brief review of it.

In the second edition of the Handbook of Space Security, authors have explained the space security from various aspects which covered perspectives of regions like Africa, Asia, Europe, North America, and South America. The four parts are “Part I International Space Security Setting, Part II Space Security Policies and Strategies of States, Part III Space Applications and Supporting Services for Security and Defence, and Part IV Space Security Programs Worldwide and Space Economy Worldwide''. These are further divided into various parts which have been contributed by 120 authors and are from around the globe. This book is a bouquet of ideas about the new paradigm of space security from a diverse viewpoint. Every topic has been covered politically, legally, economically, and technology-oriented analysis. This book is perfectly organised in terms of the author's name and their details, abbreviating and explaining each part with their sub-topics holding the detailed and descriptive explanation of every aspect.

The first part of the book "International Space Security Setting" asserts the foundational establishment of the term "space security". Here, "Security" means the civilians as well as military. In the upcoming years, the space objects will have "dual-use" which may urge the space domain to have space laws for the military as well as weaponization sectors at the same time. Space governance and sustainability go hand in hand in the space domain as well as in this book. The definitions related to space have been beautifully articulated. The first part also covers the arms control treaties for space. It also mentioned that the space laws will be changable as space will be having new technologies. They shall have new dangers which can become a threat to mankind or space objects or unknown space life. Space law is necessary to govern new technologies in space. It shall provide an advanced legal framework which shall take the place of threadbare international law which barely covers every domain of space. Space cooperation is also a big topic in the space domain. This topic is a much-neglected one in the space sector, but gladly, this book has included it with some case studies of Russia and China global space which has brought a huge change in space economy and advancement. The developed countries majorly known as space-faring nations, which have attained a certain height in this sector have decided to expand their territory in developing and under-developed countries. This is a "chain" which is known as cooperation. This is the trending and the best way to develop the space sector globally. The technological advancement in space can become a hindrance for the exportation of space technologies for the preservation of the security of the nation. This book also has a chapter dedicated to the "critical space infrastructure" which says that space may have any kind of "critical infrastructure" and tries to analyse it elegantly.

The second part begins with the cold war period. This part is more focused on the analysis of the space security strategies and policies of various regions of the world. It also includes the various inventions, dangers, policies, strategies for tackling the situation and also recommendations. It has also discussed space weaponisation and terrorism. Safeguarding the space from terrorism through a certain set of policies and laws can be a preventive measure. The nation should protect itself from their enemy nations as the level of terrorism is advancing and has reached to space with the help of activities like spoofing and jamming. Data is not secure in this advanced technological age. They have elaborately discussed it with several case studies of numerous parts of the globe.

The third part of the book discusses about space services like Earth Observation, PNT and SSA, etc. This part has truly shown the amalgamation of the law and technology. It has elaborately explained about the civil and defence privileges in space. It has mostly discussed about space assets and space services. The law behind their safe usage and also to have structures while advancing the technologies of those. There are various new emerging ways for terrorism and data hacking, which needs a protective legal structure.

The fourth part has a mention of the emerging private space realm. In the present context, the commercial space and launches have "dual-use" which poses tough threat to figure out the independent space security strategy. Initiating with ICBM, the security domain in space have headed towards the most advanced technologies now-a-days. Satellites with minimum functionality of science and military aspects have broadened their sectors in Earth Observation, telecommunications and navigation etc. This part of the book has sophisticatedly explained the launch services of all the regions, the global space economy and also the contributions of various countries in it. It has also put light on the United Nations stand on it and what measures have been adopted and implemented.

In a nutshell, this book has pioneered the space security domain with the detailed explanation of the several concepts maintaining the diversity, integrity and real essence. The continuation of chapters as a complete series of topics has made the structure well-defined. These chapters have been allocated for specific topics which make the reader easy to follow. It is recommended to read for the space enthusiasts even you are from law, policy or technology stream.

Plasma in astrophysics and it's space occurance

noreply@blogger.com (Bibhunanda) — Sat, 23 Jan 2021 14:59:00 +0000

"There are endless planes of attention, endless realities and endless mind states. They are like collections of atoms and protons and neutrons. They just go on forever. They are plasma..., they are fluid.....they are alive." - Frederick Lenz

What is PLASMA?

A hot ionised gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons often we called it as fourth state of matter. Plasmas have no definite volume or shape but these are electrically conductive and magnetically active.

Plasmas have two properties quasi-neutrality and collective behaviour that differ it from other states of matter. Quasi-neutrality is the apparent charge balance of plasma and all particles of plasma behave in similar manner showing collective behaviour.

cosmolearning.org

Discovery

In 1879, Sir William Crookes discovered the existence of plasma in Crookes tube and called as radiant matter. In 1927, Irving Langmuir Coined the term “PLASMA” as it remind him as blood plasma.

"I have never thought that you could obtain the extremely clumpy, heterogeneous universe we have today, strongly affected by plasma processes from the smooth, homogeneous one of the Big Bang, dominated by gravitation."- Hannes Alfven

How plasma formed?

When more heat is provided to atoms or molecules, they get ionised. Electron gain enough energy to escape from the atoms and after escape of electrons, atoms become ions. In sufficiently heated gas, ionization happens many times creating clouds of free electrons and ions. The ionised gas mixture consisting of ions, electrons and neutral atoms is called the 4th state of matter i.e PLASMA.

If we further increase temperature and condensed then we can produce another higher state i.e the 5th state of matter called Bose-Einstein condensate(BECs).

Also read- Fifth state of matter: BEC- A recent revelation.

Different types of plasma

Plasma can be divided into different types like astrophysical, terrestrial and artificial plasma. Terrestrial plasma occur in lightening bolt, auroras, ionospheres and extremely hot flames. Similarly terrestrial plasmas are the man made plasmas like plasma TVs, plasma coating, plasma torch, fluorescent light etc.

Astrophysical plasma is the plasma that present outside the solar system include All stars, Solar winds, Interstellar nebulae, Interstellar medium(space between stars), Interplanetary medium (space between planets), Intergalactic medium (space between galaxy), Accretion discs etc.

Solar wind containing plasma (wdrfree.com)

Sun is an example of stars in plasma state.

Where is Plasma found?

Space is not an empty vacuum rather it is full of plasma which conduct waves of electricity. From the begining of universe i.e from Big Bang, the universe was in the state of plasma. Later reionisation of universe takes place.

As plasma is a very hot ionised gas we can not mostly find it in nature or here on Earth. But the best example of naturally occuring plasma is lightning. The entire universe is formed from plasma about 99% of the matter in observable universe present in plasma state. In our solar system, the sun, interplanetary medium, magnetosphere & ionosphere of Earth, comet tails, certain planetary moons also consist of plasma.

Plasma Applications

Plasmas have different important applications from the field of space science, medical diagnostics to rocket science field. Plasma used in space craft, all types electric propulsion.

Plasma thrusters are one of the most important relevant application in the field of rocket technology. Plasma rockets have high thrust and high impulse and can capable of reaching over long period of acceleration. Electrothermal plasma thruster named VASIMR that uses radio waves forms plasma which used in spacecraft propulsion.

variable Specific Impulse Magnetoplasma Rocket
(en.wikipedia.org)

Besides all these plasmas also used in many other fields of industrial applications, new material synthesis, to drive laser and particle accelerator, different LCD fabrications and manufacturing different semiconductors etc.

Plasma is the object of study as plasma physics including sub-discipline as space plasma which includes many important applications in the area of space science to the field of medical diagnostics currently involves in the various field of active researches and challenges across many journals. Plasma is now considered as new area of research and development due to it's great features, wide range of applications, powerful energy source.

Exoplanet Exploration: Finding Planets Beyond Our Solar System

noreply@blogger.com (Unknown) — Tue, 19 Jan 2021 09:52:00 +0000

An artistic view of the Jovian exoplanet GJ 504b.

The disclosure of exoplanets is perhaps the best upset in current astronomy. Twenty years back, we had no clue about whether any of the incalculable stars out there past our nearby planetary group had planets or not. Today, things are very surprising. More than 1,000 planetary frameworks have been found. The universe is overflowing with planets. What's more, what bizarre planets they are - hot Jupiter-like planets skimming the surfaces of their stars, cold and forlorn free-gliding planets a long way from any star, planets made of jewel, planets with downpour made of glass, super-Earths and even planets circling neutron stars.

What is an Exoplanet?

The entirety of the planets in our nearby planetary group circle around the Sun. Planets that circle around different stars are called exoplanets. Exoplanets are exceptionally difficult to see straightforwardly with telescopes. They are covered up by the splendid glare of the stars they orbit. So, cosmologists utilize alternate approaches to distinguish and consider these inaccessible planets. They look for exoplanets by taking a gander at the impacts these planets have on the stars they circle.

An artist's representation of Kepler-11, a small, cool star around which six planets orbit.

Finding Exoplanets

Finding exoplanets is troublesome work. Given the difficulties, unfortunately we've discovered any whatsoever. However, space experts are shrewd, so there are presently in excess of 4,300 affirmed exoplanets. They range from little Mercury-sized universes to planets bigger than Jupiter, yet a large portion of them make them thing in like manner: they circle near their home star.This isn't on the grounds that most planets circle near their stars, yet that our perceptions have a predisposition toward close-circling planets.

An orbiting planet (small blue ball) causes a star (large yellow ball) to orbit slightly off-center.

Transit Method

The most well-known approach to find exoplanets is known as the transit strategy. This is where a planet passes before our view of a star, making the star faint somewhat. It's a straightforward thought on a basic level, however practically speaking it's troublesome. Stars change in splendor without anyone else because of things, for example, flares and starspots. To affirm a planet, you need to see a common example in the manner a star darkens, and that implies you need to notice a few travels of a planet. On the off chance that a planet orbits the star like clockwork or months, at that point you can affirm a planet decently fast. In any case, if a planet circles a star each couple of years, it could require 10 years or a greater amount of perceptions certainly.

The observed flicker of a star during the transit of an exoplanet. Credit: EPIC

Indeed, even with this predisposition, we've taken in an extraordinary arrangement about planetary frameworks. We know there are "hot Jupiters" that circle near their stars surprisingly fast, and carbon universes that would appear to be extremely unique from Earth. We likewise now realize that our nearby planetary group with its rough internal planets and vaporous external planets isn't common for most star frameworks. In any case, there is little we think about planets with circles that are a year or more. In any case, that is beginning to change, as found in a new paper.

Kepler Mission

The vast majority of the exoplanets we are aware of were found by the Kepler mission. While Kepler found a couple exoplanets with orbital periods longer than 100 days, they are more hard to affirm. Additionally, since the travel technique just reveals to us the size of a planet comparative with its star, the Kepler information doesn't allow us to decide a planet's mass. This is especially inconvenient for Jupiter-sized planets. Since the heaviness of a huge planet makes it pack more, a Jupiter-mass planet and an earthy colored bantam multiple times more monstrous can have generally a similar size. Deciding the mass of these exoplanets is the objective of the Giant Outer Transiting Exoplanet Mass Survey, or the GOT'EM Survey for short.

Artist's rendition of the Kepler spacecraft

Radial- Velocity Method

In this most recent work, the group utilized an alternate method to consider exoplanets known as the radial-velocity strategy. As a planet circles its star, it pulls on the star gravitationally, making the star wobble marginally. At the point when a star wobbles toward and away from us, the light of the star is moved to a spot to the blue and red in a normal example because of the Doppler effect. This technique is especially helpful for huge planets, and it very well may be utilized to gauge a planet's mass since the measure of wobble relies upon the mass of the planet.

The relative velocity measure of Kepler-1514. Credit: Dalba, Paul A., et al

The group zeroed in on an exoplanet known as Kepler-1514b, which circles its star like clockwork. It was found in 2016, and is known to have a distance across about 10% bigger than Jupiter. Utilizing one of the Keck Observatory telescopes in Hawaii, they made outspread speed estimations of the star Kepler-1514 and decided the exoplanet has a mass of about 5.3 Jupiters.

Need for space exploration : Benefits and critics

noreply@blogger.com (Bibhunanda) — Fri, 15 Jan 2021 13:27:00 +0000

Space is a vast structure of outer space for human imagination for the knowledge of space facts and a fertile ground for technological exploration by facilitating space programmes.

Need for space exploration is gradually increasing with the increase of civilisation and expansion in the era of digitalisation.

Aspects of future related to educating young minds regarding space sciences and it’s advance technologies of space tech fields are also very important ultimately leading to exploring space, discovering new facts & enhancing new challenges for upcoming future generations. Now we are in the era of digital fields and we are on cusp of exploring the abundance in research, resources & innovating ideas of technological connections in space with Earth-bound resonance.

The exploration of space is the great race, a secular quest which unites us under the umbrella of humanity which is transforming life; not just in orbit but here on Earth also.

“Space exploration is a force of nature unto itself that no other force in society can rival.”-Neil deGrasse Tyson

speakertv.com

Benefits:

Important benefit of space exploration is it help us from different potential hazards like appearance of stellar objects, comets, falling of asteroids and allow us to prepare for the situation in advance. To know the origin and beginning of universe, to find our place in universe, we need to explore space and universe. We discover various informations regarding structure of outer space systems, about the facts of our home planets, galaxies, new planets, stars and different celestial bodies and we can get to know details on their surface, structure, culture simultaneously.

Satellite technologies:

Applications of satellite are vast including communication, navigation and different military and civilian purposes. Satellites make life easier through signal communications like radio, television and help us in knowing weather monitoring and climate changing.

Biomedical applications:

Biomedical research in ISS (blogs.nasa.gov)

Exploring space provides human to maintain good health. Other indirect benefits we can find like muscle physiology, robotic medicine, wireless telemetry from space research.

Besides all this advancement of scientific technologies and experience, development new applications, economical benefits in aerospace market, international partnership in different mission are the direct benefits of exploring space and technology.

Indirect benefits include security and safety via new technologies, advancement of biomedical engineering and research to improve health issues, human space travel etc.

Critics starts with the money trails:

All benefits of space exploration go in vain when the costs invested come into picture. The expanses on this field are too high even to plan the launch of any space shuttle. To launch a space shuttle the required budget is around $500 million. So many comments we can see that the costs spent on this field can never justifiy the poverty and hunger that to fulfill the basic needs of humans to survive.

Some commets are like- “Humanity would be better off saving Earth, rather than colonizing Mars that: It is better to hold off disasters at home than to assume all is lost.”

50 years after moon landing
Investment of different countries (fortune.com)

The figure represents the money spent on the space race 50 years after the moon landing. Total 18 countries are in the race and they contributed around $300-400 million on this field and in different activities with the U.S. contribution is on top rather than other countries. A lot more spent by different space companies, privately engaged space sectors of different countries invested to very large extent in recent years. Old report suggest in 2019 around $5.8 billion ventured by spaceX and raised upto $1.9 billion in the previous year.

The companies are working on the field of space tourism and enhancement of advance technologies, operations to mine celestial bodies and different missions to discover various planetary objects.

Another important factor is space debris that is harmful for many systems, spacecrafts and satellite systems regarded as the major barrier in space exploration. Critics says such type of technologies raise the pollution in space create a huge cloud of fragments that persist for many years affecting outer space and systems also.

Also Read- Space debris: cause and solution

"It's human nature to stretch to go, to see, to understand. Exploration is not a choice really; it's an imperative."- Michale Collins

Exploration of space includes the gradual increase of space tech based industries, enhancement of advance technologies and expansion of scientific knowledge regarding space. Research on this field motivates people around the world and inspires young minds to become curious for gaining knowledge, no matter what country or religion we have, study and exploration of space combines us in one platform, unites all around the globe.

Auroras: The Dazzling Lights

noreply@blogger.com (Unknown) — Thu, 07 Jan 2021 12:32:00 +0000

sciencefriday.com

What is an Aurora?

An aurora is a natural light display that shimmers in the sky. Colorful blue, red, yellow, green, and orange lights shift gently and change shape like softly blowing curtains. The word "aurora" is derived from the name of the Roman goddess of the dawn, Aurora, who travelled from east to west announcing the coming of the sun. Ancient Greek poets used the name metaphorically to refer to dawn, often mentioning its play of colours across the otherwise dark sky. Auroras are visible almost every night near the Arctic and Antarctic Circles, which are about 66.5 degrees north and south of the Equator. In the north, the display is called aurora borealis, or northern lights. In the south, it is called aurora australis, or southern lights.

How Auroras are formed?

The activity that creates auroras begins on the sun. The sun is a ball of superhot gases made up of electrically charged particles called ions. The ions, which continuously stream from the sun’s surface, are called the solar wind.
As solar wind approaches the Earth, it meets the Earth’s magnetic field. Without this magnetic field protecting the planet, the solar wind would blow away Earth’s fragile atmosphere, preventing all life. Most of the solar wind is blocked by the magnetosphere, and the ions, forced around the planet, continue to travel farther into the solar system.

Although most of the solar wind is blocked by the magnetosphere, some of the ions become briefly trapped in ring-shaped holding areas around the planet. These areas, in a region of the atmosphere called the ionosphere, are centered around the Earth’s geomagnetic poles. The geomagnetic poles mark the tilted axis of the Earth’s magnetic field.

In the ionosphere, the ions of the solar wind collide with atoms of oxygen and nitrogen from the Earth’s atmosphere. The energy released during these collisions causes a colorful glowing halo around the poles—an aurora. Most auroras happen about 97-1,000 kilometers above the Earth’s surface.

The most active auroras happen when the solar wind is the strongest. The solar wind is usually fairly constant, but solar weather—the heating and cooling of different parts of the sun can change daily. Magnetic storms and active auroras can sometimes interfere with communications. They can disrupt radio and radar signals. Intense magnetic storms can even disable communication satellites.

spaceplace.nasa.gov

Coloring an Aurora

The colors of the aurora vary, depending on altitude and the kind of atoms involved. If ions strike oxygen atoms high in the atmosphere, the interaction produces a red glow. This is an unusual aurora—the most familiar display, a green-yellow hue, occurs as ions strike oxygen at lower altitudes. Reddish and bluish light that often appears in the lower fringes of auroras is produced by ions striking atoms of nitrogen. Ions striking hydrogen and helium atoms can produce blue and purple auroras, although our eyes can rarely detect this part of the electromagnetic spectrum.

Forms of auroras

Source: Wikipedia.org

There are four main forms that can be seen from the ground, from least to most visible:

A mild glow, near the horizon. These can be close to the limit of visibility but can be distinguished from moonlit clouds because stars can be seen undiminished through the glow.

Patches or surfaces that look like clouds.

Arcs curve across the sky.

Rays are light and dark stripes across arcs, reaching upwards by various amounts.

Coronas cover much of the sky and diverge from one point on it.

Some auroras are referred as curtains. The similarity to curtains is often enhanced by folds within the arcs. Arcs can fragment or break up into separate, at times rapidly changing, often rayed features that may fill the whole sky. These are also known as discrete auroras, which are at times bright enough to read a newspaper by at night. These forms are consistent with auroras' being shaped by Earth's magnetic field. The appearances of arcs, rays, curtains, and coronas are determined by the shapes of the luminous parts of the atmosphere and a viewer's position.

Do other planets get auroras?

They sure do! Auroras are not just something that happen on Earth. If a planet has an atmosphere and magnetic field, they probably have auroras.

These swirls of red light are an aurora on the south
pole of Saturn. Image courtesy of NASA/ESA

The NASA Hubble Space Telescope took this picture of
an aurora on Jupiter using ultraviolet (UV) light.

Both Jupiter and Saturn have magnetic fields that are stronger than Earth's and both have extensive radiation belts. The aurorae on Saturn seem, like Earth's, to be powered by the solar wind. However, Jupiter's aurorae are more complex. The Jupiter's main auroral oval is associated with the plasma produced by the volcanic moon, Io and the transport of this plasma within the planet's magnetosphere. In addition, the moons, especially Io, are also powerful sources of aurora. These arise from electric currents along field lines generated by a dynamo mechanism due to the relative motion between the rotating planet and the moving moon.

Auroras have also been observed on Venus and Mars. Venus has no magnetic field and so Venusian auroras appear as bright and diffuse patches of varying shape and intensity, sometimes distributed over the full disc of the planet. A Venusian aurora originates when electrons from the solar wind collide with the night-side atmosphere.

An aurora was detected on Mars, on 14 August 2004, by the SPICAM instrument aboard Mars Express. Also the first ever extra-solar auroras were discovered in July 2015 over the brown dwarf star LSR J1835+3259.

Located just 20 minutes from Iceland’s capital city of Reykjavík – the Aurora Basecamp.
Source: icelandnaturally.com

Witnessing the northern lights is a transformational bucket-list experience that many people wait years—even a lifetime to see, since the conditions need to be perfect for this spectacular display to take place. The best places in the world are usually closer to the Arctic Circle, including Alaska, Canada, Iceland, Greenland, Norway, Sweden and Finland. One can also spot the southern lights in the southern hemisphere. Still, the northern lights are the star of the show.

In order to increase chances of seeing this spectacle one should time trip to a new moon. Since the northern lights can appear and disappear in a snap, it’s important to be on alert throughout the night. Another tip: Weather is also key. Try to find a place where the sky is clear, dark and free of clouds.

Remote Sensing Draft policy 2020

noreply@blogger.com (Ashmita Deb) — Thu, 07 Jan 2021 08:32:00 +0000

“Towards meeting this responsibility and obligation, the realisation of any space asset by an Indian entity, operating in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geostationary Orbit (GEO) or in any other orbit and use of space-based remote sensing in any part of the electromagnetic spectrum, to or from Indian territory, will be permitted through a process of authorization.”

Legal framework on Remote Sensing in Indian Space: Enough!

Indian map picture from a satellite
Credit: Shutterstock

Any private space startups active in the remote sensing field have to look for the “norms, guidelines and procedures” document for their activities. ISRO amalgamating with the Department of Space and Indian Government has come up with drafts of various space policies intending to make India self-reliant. Space Remote Sensing Policy - 2020 has been drafted to provide a legislative structure to accelerate the privatisation of the space sector. The draft preserves the national security of the nation through protecting sensitive data and information.

(Also read - ISRO Spacecom Policy explanation)

Earth image from space
Credit: Shutterstock

The backdrop of remote sensing in India

The role of remote sensing found its importance in the year of 1970 for the detection of the “coconut root-wilt disease” in India. Gradually, it’s importance expanded because of its multispectral camera system for various applications in society as India’s Foreign Policy has a societal-development perspective. Based on this observation, India launched its first Indian Remote Sensing Satellite in 1988 for the development of ocean, disaster management, atmosphere, land, water, etc. by acquiring data regarding the issues in these domains. It has focused on sensor technology and data processing techniques. National Natural Resources Management System(NNRMS), an institution which ensured the usage of data by various Central and State Government ministries, Non-governmental organisations and private sectors which was acquired through remote sensing. From the year 1988, a huge change has been experienced in this field. The data has opened for better accessibility and performance from Earth observation satellites results in the development of the space field and innovative applications, economic development and enhancing private participation.

India from space
Credit: Shutterstock

Some important points on the Space Remote Sensing Policy - 2020

· To narrow down the gap between the demand and supply of data and technologies by building the base of remote sensing technology in Indian industries.

· End-to-end services will be provided to fully operate the space assets, establishing ground stations, accumulating satellite data and establishing the remote sensing facilities in the Indian territory and abroad.

· A simple registration or authorisation allows any service provider from India to provide data and services regarding the remote sensing to any country or company abroad excluding the “sensitive data”.

· Right to impose or control will be regulated on imaging and observation aspects for national security.

· All the services will be treated as commodities but will also be provided for social-development purposes.

· For sustainability, new innovative technologies and applications will develop through the Indian government.

· Private sector can fully operate the remote sensing systems

· Private sectors can perform operations like telemetry, tracking and command(TT&C).

· Private sectors were allowed to establish “Satellite Data Reception Stations” anywhere in India and outside the Indian territory.

· NGPEs can take the initiative in designing, development of satellites and remote sensing systems.

· Private sectors must provide the details of the payload, spacecraft, spectral bands, orbital parameters, coverage area, etc. to the government for national security while authorising.

· NGPEs are liable for any kind of damage done to space objects.

· Financial guarantee or insurance cover is a part of the authorization.

· The change of ownership may lead to a new process of authorization for the private sectors.

· The prescribed formats have been provided for the submission of proposals and registration of space assets.

· Specific authorisation is required for acquiring high-resolution data of less than fifty centimetres and it is treated as “sensitive”.

Credit: Rajyasabha TV

Remote sensing for society

For societal development purposes, remote sensing is an essential tool for “national development”, “strategic applications”, “technology demonstrations”, “disaster management support”, “weather monitoring” and “improved observing and imaging capability”. Ground Sample Distance(GSD) of 5 meters of data through remote sensing will be openly accessible as free. Through designated PSU or CPSE Remote Sensing satellite, data will be available for commercial purpose. “As is where is” is a category which is imposed as a condition for using data for research, making development and to add any value to the nation. Many facilities will be provided to the commercial sectors at no or notional cost.

(For more details - refer ISRO Remote Sensing Policy)

What are your insights on it? Let me know in comments!

Celestial events calender: 2021

noreply@blogger.com (Bibhunanda) — Fri, 01 Jan 2021 09:47:00 +0000

We have successfully completed one more orbit around the Sun. We observed the changes occured in our life and in space too. Now it's the time to orbit and explore the entire Universe again.

We have already watched many more exciting events in the previous year 2020 that will be unforgettable includes appearance of comet neowise to conjuction of Jupiter and Saturn.

Let’s discover what are the important notable events that are going to happen in the upcoming year 2021!!

JANUARY

3,4 - Quadrantids meteor shower

1st meteor shower of the welcoming new year is Quadrantid meteor shower and around 40 Quadrantids per hour will appear in the dark night sky.

13- New moon phase

Best day to observe the clusters of stars and galaxies as there is no moonlight in the new moon phase.

Showing different phases of moon
(moonconnection.com)

24- Mercury at greatest eastern elongation

Best time to observe Mercury as Mercury is at greatest elongation at eastern side at this time.

28- Full moon phase(wolf moon)

Fully illuminated moon will appear in the night sky and we called it as wolf moon.

FEBRUARY

11- New moon phase

27- Full moon phase

The full moon appear in February month is called snow moon.

MARCH

6- Mercury at greatest western elongation

Mercury is at greatest elongation at western side at this month at this time.

13- New moon phase

20- Vernal(N), Autumnal(S) equinox (march equinox)

Spring equinox in northen hemisphere and fall equinox in the sauthern hemisphere when day and night are of equal length.

20- Venus at greatest western elongation

28- Full moon phase(worm moon)

APRIL

12- New moon

17- Occultation of mars by moon

Occultation is a phenomena when an object hidden behind another object while passing through it due to the orbital motion of both the objects. Moon and Mars will come closer on 17th of this month.

Showing Moon & Mars occultation (nypost.com)

27- Full moon (super) Pink moon

Full moon of the month April is called pink moon.

22, 23- Lyrid meteors

The second meteor shower of the year we can observe it during 22nd and 23rd of April. Lyrids can be observe better in Northern hemisphere which are in the constellation Lyra.

MAY

6,7- Eta Aquarid meteors

Eta Aquarids are the meteors of constellation Aquarius which are created by the debris from comet Halley.

skyandtelescope.org

11- New moon phase

17- Mercury at greatest eastern elongation

Mercury is at greatest elongation at eastern side at this time.

26- Total lunar eclipse

This is the first lunar eclipse after two years. Last lunar eclipse was held on January 2019 and it will be visible in many areas including South Asia, East Asia, Australia, North & South America and some parts of Antarctica.

26- Full moon (super) phase (Flower moon)

JUNE

10- New moon phase

10- Annular solar eclipse

This year on 10th Jan annular solar eclipse will occur in which moon will be in the middle of Sun and Earth as a result Sun light will not be able to reach the Earth occuring solar eclipse.

21- Summer(N) winter solstice(S)

We can observe longest day time in Northern hemisphere occuring summer soltice.

24- Full (Super)moon phase, Strawberry moon

The full moon of the month has another name called super strawberry moon which is the biggest supermoon of 21st century.

JULY

4- Mercury at greatest eastern elongation

10- New moon phase

13- mars venus conjunction

Venus will be in conjunction with Mars on 13th of this month.

24- Full moon phase(Buck moon)

Buck moon will rise at the end week of the month also called rose moon and thunder moon.

28, 29- Delta aquarids meteors

This meteor shower events are considered as the longest events and will appear for around two weeks but 28 and 29 of this month will be the best time observe the meteors.

AUGUST

2- Saturn at opposition

Any outer planet beyond Earth’s orbit is near opposition, the planet comes closer to Earth at that time and the planet shines bright and visible in the sky. Saturn will make closest approach to Earth and it lies opposite to Sun.

8- New moon phase

12, 13- Persid meteors

The prolific meteor shower persids will appear in the middle of this month which are from the constellation perseus.

18- close conjunction of mars and mercury

19- Jupiter at opposition

Jupiter will appear darker and brighter on 19th of the month.

accuaweather.com

22- Full moon phase(Blue moon)

The seasonal blue moon of August also called sturgeon moon will appear fully on 22nd of August.

SEPTEMBER

7- New moon phase

14- Neptune at opposition

14- Mercury at greatest eastern elongation

20- Full moon phase(Harvest moon)

we can see the fully illuminated moon which will be on the opposite side of the Earth. It is well known as corn moon or harvest moon by early native American people because it occurs when corn is harvested on this time of the year.

22- Autumnal (N) Vernal (S) equinox

The sun will rise on east and sets on west and the length and time of day and night are of equal over the world on 22nd September called equinox.

timesanddate.com

OCTOBER

6- New moon phase

7- Draconids meteors

Draconids which are the annual meteors normally appear on the month of october also called as Giacobinids.

10- Taurid fireball season peaks

Taurids are the annular meteors of the month of october associated with comet Encke and on mid november we can see around 5 meteors per hour and it also known to produce fireballs.

20- Full moon phase(Hunters)

Good oppertunity for sky watchers to watch the blood moon of the year. This is also called haunters moon or harvest moon.

21, 22- Orionids meteors

Orionids which belongs to the constellation Orion will be in peak on 21-22 of the month.

25- Mercury at greatest western elongation

NOVEMBER

4- New moon phase

4,5- Taurids meteors

Taurids meteors from the constellation Taurus will appear on the night sky on 4th & 5th of the month often we called Halloween fireballs. These meteors have two different showers; in northern part, Taurids originated from asteroid and in sauthern part it created from comet Encke.

5- Uranus at opposition

17,18- Leonid meteors

Spectacular meteors Leonids will appear on it's peak on 17-18th of this month.

19- Full moon phase (Beaver moon)

The fully illuminated moon which signifies the begining of the winter also called frost moon and will appear in East Asia, America, Australia and some part of northen Europe.

19- Partial lunar eclipse

DECEMBER

4- Total solar eclipse

4- New moon phase

13,14- Geminid meteors

Geminids shower is the most important and spectacular meteor shower appear in the sky. Geminids meteor shower wil visible on 13th December and upto early morning of 14th December. But one can see this from 4-17 December for around two weeks but best to watch between 13 &14th of the month. We can see around 120-130 meteors per hour on these days when they are active on their peak.

19- Full moon phase

21- Winter (N) Summer (S) solstice

This is the phenomena occurs on 21st December of the year and this is the day of shortest day and longest night often we called as mid-winter.

21, 22- Ursid meteor shower

The meteor from the constellation Usra Minor will be active on it's peak on the date 21 & 22 December of the year. It will be visible for a week from 17-24 December. The rate of this Ursid meteors are very low in comparision to geminids and can be observed around 10-20 meteors per hour.

This calender refers to all the important spectacular celestial cosmic events which we are going to observe this year. Don't miss any event, mark your calender and watch the exciting phenomena occur in the space and stay connected with us for further detail discussion on the similar amazing astronomy events of every month of 2021.

Space time :Mathematics of Universe

noreply@blogger.com (Bibhunanda) — Tue, 29 Dec 2020 11:31:00 +0000

We experience and observe three dimensions of space generally like left-right, top-down, back-forward in our everyday life that we called those as spatial dimensions that are on ordinary space. It is not quite complete in case of universal space. We need a fourth value to specify the occurance of an event specially in universe. We consider that fourth one is time which doesn’t behave like other dimensions and extends beyond length, width and height and called as fourth dimension that is not a spatial one rather called temporal dimension. The four dimensional space diagram was first used by H. Minkowski in the year 1908 often we called world space or Minkowski space.

Showing Minkowski Space (relativity.com)

"The views of space and time which i wish to lay before you have sprung from the soil of experimental physics, and therein lies there strength. They are radical. Henceforth space by itself, and time by itself are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality."- Hermann Minkowski, 1908

If we consider two events, we can determine the quantity Δs² between the two events and we find that it is invariant in any inertial frame. The quantity Δs is known as the space-time interval between two events.

Considering space and time together and taking into account that the speed of light must be constant in any frame. We find the line element to satisfy such conditions is

ds² = c²dt² - dx² - dy² - dz²

There are three possibilities for invariant quantity Δs². .

Timelike Interval

The relation is Δs²<0:Δx²<c²Δt², two events can be casually connected and the interval is said to be timelike.

Spacelike Interval

The relation is Δs²>0:Δx²>c²Δt² and no signal can travel fast enough to connect the two events. The events are not casually connected said to have a spacelike separation.

Lightlike Interval

The relation is Δs²=0:Δx²=c²Δt² and the two events can be connected only by a light signal. The events are said to have a lightlike separation.

We normally think that space and time behave totally independent. But Einstein put forward a theory that infact linked these together and that called space-time. A mathematical model was given which is a totally four dimensional structure that is a combination of three dimensional space and one dimensional time. Massive objects curved space time. This means that distances between two points and also times between two events are wrapped around massive objects and this has a strange consequences like time ticking differently on different planets and massless photons being bent by massive objects because of that space-time curvature.

The equation that describe all this –

R_{\mu \nu }-{\tfrac {1}{2}}Rg_{\mu \nu }+\Lambda g_{\mu \nu }=\kappa T_{\mu \nu }.

The left side of the equation tells about the curvature of space-time and right side of equation is a tensor relates the mass energy formula. The total expression reveals that the energy-momentum tensor is proportional to how the curvature (on left side expression) bends.

R_μν is the Ricci tensor defines the bending of space-time axis, $g μν$ is a metric tensor used to observe and measure the length of object in that geometry. 1/2 R is the correction factor introduced.

Positive and negative curvature:

Positive curvature in space time is caused by the gravity of mass and energy. Spheres we can say have positive curvature while saddles have negative curvature shown in figure below.

Showing positive and negative curvature (commons.wikimedia.org)

The theory of space-time explains the object moving with speed of light with the motion of massive object which is a relativistic effect predicted by Einstein which was one of the part of his theory named theory of relativity.

Working of space-time:

A sheet of rubber best way that describes about the space-time curvature as a overview but it’s not actually if we discuss in analogy, the sheet of rubber is a two dimensional while space-time is four dimensional. Massive objects create curvature that is the cause to bend and objects move along the bending curvature. Gravity; a curved field described by an area of space under the influence of force in the space time fabric that is actually created by the presence of mass of matter and the motion of gravity occurs due to the twists and turns of curvature of space-time.

youtube.com

The mission Gravity probe B (GP-B) was a mission to measure the shape of space-time vertex around the Earth and the mission used a telescope and four spherical gyroscopes and found according to the prediction given by Einstein.

"A human being is a part of the whole called by us universe; a part limited in time and space. He experiences himself, his thoughts and his feelings as something separate from the rest - a kind of optical delusion of consciousness."- Albert Einstein

The God Particle: Higgs Boson

noreply@blogger.com (Unknown) — Sun, 27 Dec 2020 12:00:00 +0000

irb.hr

The Higgs field is a field of energy that is thought to exist in every region of the universe. The field is accompanied by a fundamental particle known as the Higgs boson, which is used by the field to continuously interact with other particles, such as the electron. The Higgs boson is an elementary particle in the Standard Model of particle physics, produced by the quantum excitation of the Higgs field. Particles that interact with the field are "given" mass .The result of a particle "gaining" mass from the field is the prevention of its ability to travel at the speed of light. Mass itself is not generated by the Higgs field; the act of creating matter or energy from nothing would violate the laws of conservation. Mass is, however, gained by particles via their Higgs field interactions with the Higgs Boson. If the Higgs field did not exist, particles would not have the mass required to attract one another, and would float around freely at light speed. Also, gravity would not exist because mass would not be there to attract other mass. Giving mass to an object is referred to as the Higgs effect. This effect will transfer mass or energy to any particle that passes through it. Light that passes through it gains energy, not mass, because its wave form doesn't have mass, while its particle form constantly travels at light speed.

science.fandom

"Symmetry breaking illustrated"

Creation of Higgs boson

The way that the SU(2) symmetry is broken is known as "spontaneous symmetry breaking". Spontaneous means random or unexpected, Symmetries are the rules that are being changed, and Breaking refers to the fact that the symmetries are no longer the same. The result of spontaneously breaking the SU(2) symmetry can be a Higgs boson. Spontaneous symmetry breaking is a spontaneous process of symmetry breaking, by which a physical system in a symmetric state ends up in an asymmetric state. The $SU(n) groups,$ the special unitary group of degree $n$ find wide application in the Standard Model of particle physics, especially $SU(2)$ in the electroweak interaction and $SU(3)$ in quantum chromodynamics.

Reason for Higgs effect

The Higgs effect occurs because nature "tends" towards the lowest energy state. The Higgs effect will happen because gauge bosons near a Higgs field will want to be in their lowest energy states, and this would break at least one symmetry. Just after the big bang, the Higgs field was zero, but as the universe cooled and the temperature fell below a critical value, the field grew spontaneously so that any particle interacting with it acquired a mass. The more a particle interacts with this field, the heavier it is. Particles like the photon that do not interact with it are left with no mass at all. Like all fundamental fields, the Higgs field has an associated particle – the Higgs boson. The Higgs boson is the visible manifestation of the Higgs field, rather like a wave at the surface of the sea.

Discovery

phys.org

Although the Higgs field exists everywhere, proving its existence was very difficult. In principle, it can be proved to exist by detecting its excitations, which manifest as Higgs particles (the Higgs boson), but these are extremely difficult to produce and detect, due to the energy required to produce them and their very rare production even if the energy is sufficient. It was therefore several decades before the first evidence of the Higgs boson was found. Particle colliders, detectors, and computers capable of looking for Higgs bosons took more than 30 years to develop. The importance of this fundamental question led to a 40-year search, and the construction of one of the world's most expensive and complex experimental facilities to date, CERN's Large Hadron Collider, in an attempt to create Higgs bosons and other particles for observation and study. On 4 July 2012, the discovery of a new particle with a mass between 125 and 127 GeV/c² was announced; physicists suspected that it was the Higgs boson. Since then, the particle has been shown to behave, interact, and decay in many of the ways predicted for Higgs particles by the Standard Model.

To produce Higgs bosons, two beams of particles are accelerated to very high energies and allowed to collide within a particle detector. Because the Higgs boson decays very quickly, particle detectors cannot detect it directly. Instead the detectors register all the decay products and from the data the decay process is reconstructed. If the observed decay products (the decay signature) match a possible decay process (known as a decay channel) of a Higgs boson, this indicates that a Higgs boson may have been created. Fortunately, the Standard Model precisely predicts the likelihood of each of these, and each known process, occurring. So, if the detector detects more decay signatures consistently matching a Higgs boson than would otherwise be expected if Higgs bosons did not exist, then this would be strong evidence that the Higgs boson exists. By March 2013, the existence of the Higgs boson was confirmed, and therefore, the concept of some type of Higgs field throughout space is strongly supported.

Nickname

The Higgs boson is often referred to as the "God particle" . The nickname comes from the title of the 1993 book on the Higgs boson and particle physics, The God Particle: If the Universe Is the Answer, What Is the Question? by Physics Nobel Prize winner Leon Lederman. While media use of this term may have contributed to wider awareness and interest, many scientists feel the name is inappropriate since it is exaggeration and misleads readers; the particle also has nothing to do with any God, leaves open numerous questions in fundamental physics, and does not explain the ultimate origin of the universe. Higgs, an atheist, was also reported to be displeased .

Interesting Fact

Stephen Hawking bet Gordon Kane $100 that physicists would not discover the Higgs boson. After losing that bet when physicists detected the particle in 2012, Hawking lamented the discovery, saying it made physics less interesting.

slideshare.net

On one hand, the discovery of Higgs boson was obviously a huge win for science but on the other, there were many scientists who were disappointed that, yet again, the Standard Model has held up to another round of immense scrutiny. According to them if you were hoping for the Higgs boson to be the weird particle that led us towards the weird and wonderful nether regions of science beyond the Standard Model supersymmetry, dark matter, dark energy then sadly this is not the particle you were looking for.

India's Space policy "Spacecom Policy"- Is it enough?

noreply@blogger.com (Ashmita Deb) — Wed, 23 Dec 2020 12:04:00 +0000

Spacecom policy for private sectors

Credit: Times of India

India is having an influential and developmental space program. But, India is still lacking in space policy and legislative structure in space. In 2020, ISRO has produced a Spacecom Policy. ISRO has a history of huge influential scientists and mathematicians who played a major role in contributing to the establishment and development of it. History witnesses the hard path of advancement of ISRO struggling with their limited resources to stand on a global platform. ISRO always showed their brave side by launching their first satellite and reaching Mars with the lowest budget.

Paraphrasing Dr Sivan, private sectors also must grow from zero just like ISRO has laid the roadmap from zero stage to now and ISRO shall provide the helping hand of technology and policy for their achievement in this field. The private entrepreneurs must do the Commercial missions, operational missions, services as well as technology development with the ISRO.

Spacecom policy for Indian Space by Dr Sivan

Credit: RajyaSabha

The policy includes guidelines for the private sectors mainly. ISRO is expecting private sectors as the partner in their missions. They shall equally take part in satellite-based broadcasting, network connectivity, and global mobile personal communication. Further guidelines are -

Monitor and authorize the use of space assets from Indian territory.
Ensure protection of space assets.
Increase participation of commercial Indian industry internationally.
Private sectors shall advance in the communication sector.
They shall expand in national territory as well as in international.
They shall focus on service-based satellites to provide advanced developmental services to the people.
No restrictions shall be imposed on providing facilities to the people, ground session setup, owning satellites.
Private industries can use the existing satellites of ISRO for their developmental stages

They can further develop their satellites with the help of these technologies and data.
The private sector shall also be liable for any damage done to any other object in the space with their space object.
The private sector can use the 48% of the space sector budget for the ground stations for the space crafts.
45% of the space economy for the application of space technology as a commercial basis.
Private sector to do the Commercial missions, operational missions, provide services as well as technology development which shall help India to develop revenue for their future launches. This shall help the ISRO to advance their launches in the context of technology and fill up the loss of economy held during covid19 period.

India is having collaboration with Nasa namely NASA ISRO Synthetic Aperture Radar, which is a very costly satellite. ISRO has collaborations with France Space Agency for satellites named "Krishna'', Russian Space Agency for training astronauts, Gaganyaan program, Japanese Space Agency for Compiled collaboration for next Moon mission, Israel Space Agency for small thrusters for the small satellites. This policy wraps up a small share of space. It must be extended to the other spheres of space which is not directly related to the space realm. This work must be done by non-technical advisors, technical scientists and engineers. It must be cooperative work. A non-partisan advisory board must be set up for further proceedings regarding the policies on the various perspectives of space by the government which must include the government officials as well as the private representatives.

PSLV-C49/EOS-01 Gallery
Credit: ISRO

These policies shall help India to stand in the Global Space Communication Sector. The technology must be used by the experienced individuals or groups and it must be noted that it should not be used by any evil-minded groups. The high-resolution images or data was taken by the private sectors to do their work has a high risk of privacy. It must be ensured that the privacy of any individual or nation is not at risk. ISRO is still not capable of launching big satellites of their own. They take the help of the foreign countries and the opening up of the private sector may help the ISRO to become self-sufficient. The laws must be made in the commercial sector ensuring the correct use of the technology for the development of people only, not for individual purposes. The strategic part of the space must be bound with laws to provide a safe space. The private sector must produce technologies which are advanced as well as develop the livelihood of the people. It also must ensure the safety of the nation and people. Private sectors with technological and economical help from space. These shall lead India to become a global powerhouse in the globe and achieve technological advancement in the world. ISRO is looking for formulating more policies regarding the remote sensing, private space sector, Geospatial policy, policies for the usage of satellite for various development purposes.

What if we explode the moon with nuclear weapons?

noreply@blogger.com (Unknown) — Mon, 21 Dec 2020 13:00:00 +0000

The Moon is the first milestone on the road to the stars.

-Arthur C. Clarke

Are you a selenophile? Are you someone who feels an enigmatic attraction for the Moon and the stars? Well, you're not alone. And there are plenty of reasons for you to feel inexplicably connected to the fifth largest satellite in the Solar System. The Moon – derived from the Latin word Luna - is our only permanent natural satellite, and it was formed 4.5 billion years ago when a rock slammed into our planet. Although it appears as a white satellite, the Moon's surface is dark. People have always been fascinated by this massive silica-rich globe that "illuminates" our planet at night.

“Ten years ago, the Moon was an inspiration to poets and an opportunity for lovers. Ten years from now, it will be just another airport “quotes Emmanuel G. Mesthene and guess what it is reality now. But have you ever wondered what if we explode moon with nuclear weapons.

Source: Ridddle

Nuclear weapons are the most destructive, inhumane and indiscriminate weapons ever created. Nuclear weapons produce ionizing radiation, which kills or sickens those exposed, contaminates the environment, and has long-term health consequences, including cancer and genetic damage. Less than one percent of the nuclear weapons in the world could disrupt the global climate and threaten as many as two billion people with starvation in a nuclear famine. The thousands of nuclear weapons possessed by the US and Russia could bring about a nuclear winter, destroying the essential ecosystems on which all life depends. A nuclear weapon is defined as an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb). Both bomb types release large quantities of energy from relatively small amounts of matter. So what would happen if we carry these into space and that too for exploding moon? It is not that we are talking about fiction.

But first let’s understand the impact of a nuclear explosion on Earth. Contrary to popular belief, a nuclear explosion is not just a huge ball of fire and dust.Unlike conventional explosions, a single nuclear explosion can generate an intense pulse of thermal radiation that can start fires and burn skin over large areas. Needless to say, fatal radiation exposure in a nuclear explosion affects all living things within a radius. But that’s not all, special attention should be paid to the shockwave caused by a nuclear explosion as it can blast everything in its path. The strength of a shockwave can only be compared to powerful tsunamis capable of destroying entire cities. Furthermore, a nuclear explosion brings forth a sharp change in the environmental parameters.Thermal radiation and a shockwave destroy everything first followed by radiation consummates the rest. Intriguingly, such a scenario is only relevant for explosions on the Earth. Outside the Earth, the events take place a little unusually. In the 1950s, Scientists from NASA studied the behaviour of a nuclear bomb in space. In the course of the research, it turned that due to the lack of atmosphere in space there was neither a typical mushroom cloud(a distinctive pyrocumulus mushroom-shaped cloud of debris, smoke and usually condensed water vapor resulting from a large explosion) nor a blast wave(an area of pressure expanding supersonically outward from an explosive core). But the danger of radiation remains even in the cosmos. Radiation in vacuum propagates several times faster than on the Earth. Consequently, a nuclear explosion occurred anywhere near our planet would be lethal for humanity.

Source: Science ABC

Now imagine that some maniac is able to lay a nuclear bomb in the bowels of the Moon. If the explosion transpires to be weak, our satellite will split into several large pieces.Subsequently resulting in the presence of not just one moon but several mini-moons. Envision the change in the night sky with the addition of several mini moons.The mechanics of the solar eclipse would also change as several parts of the moon will no longer be able to form together and block the sun. But, what if the detonation has an explosive force of four thousand Tsar bombs. This mega explosion abstains the Earth from losing its gravitational field. Small fragments of the moon might simply attract to our planet and orbit around it like space debris. As for the larger pieces, that condition will be hazardous for our planet. Larger fragments of the moon would leave their orbit and fly towards our Earth with tremendous speed.Snaring a couple satellites along, these fragments will then collapse on cities. Humanity has already had several encounters with space objects: the Tunguska event and the Chelyabinsk meteorite. But the reverberations of descending lunar debris would be unpleasant.

Succeeding the explosion, our planet won't have a moon. What are the consequences of losing a moon? How important is the moon to our planet? With the deprivation of a moon, the ebbing flow of the tides in the oceans will be negligible. Moreover, this would result in nutrients and oxygen to locomote weakly across the water bodies all over the Earth. It’s probable that many rivers and seas won’t have currents ensuing the water to become stagnant like a dirty aquarium. What happens to sea animals in such conditions? They perish. Hence, the marine inhabitants of our planet face the danger of extinction. Furthermore, every animal whose source of nourishment is fish also perishes. If our satellite disappears, the natural order of things to which Homo Sapiens are accustomed to will collapse as the length of the day will change. Without the moon, the axial tilt of the Earth will lose stability and the climate will actively begin to transform. The moon is a good stabilizer for our planet. As of now, the axial tilt of our planet is 23.4 degrees. With the disappearance of our natural satellite, according to scientists, the axial tilt will increase to 45 degrees. Such an increase in the figure will cause the poles to no longer be constantly cold and the equator will no longer be constantly hot. Thereby, the possibility of an ice age cannot be implausible. Moreover, this whole event could repeat itself in different parts of the plane every thousand years. It’s likely that the disappearance of eclipses and night becoming darker will be the centre of our attention in the middle of so many chaotic events.

Source: United States Department of Energy

The ramifications of exploding the moon with nuclear weapons is certainly a petrifying scenario. Thus, to avoid such turn of events in 2016 MILAMOS(Manual on International Law Applicable to Military Uses of Outer Space) project was launched. MILAMOS project aims to develop a widely-accepted manual clarifying the fundamental rules applicable to the military use of outer space in peacetime.This project also further strengthens the 1963 law prohibiting nuclear weapons in space, their transportation and installation on space objects which also includes the moon. Due to this even a maniac with the demented objective to blow up the moon would abstain from taking such actions. Eurasian Times published that US President Donald Trump has issued the SPD-6, which lays out a national strategy for the responsible and effective use of space nuclear power and propulsion (SNPP) systems. It comes at a time when China’s Chang’e-5 successfully completed its moon mission and returned with lunar samples. The Chinese expert claims that the signing of SPD-6 shows the US’ intent to drag China into a space race. . A Chinese media report says that the US’ ambitions may lead to future lunar military projects as it seeks space supremacy regardless of the damages it would cause.

While the US claims that the plant would “support a sustained lunar presence and exploration of Mars”, China speculates military purposes behind the establishment. Chinese military expert Song Zhongping told that the moon is rich in helium-3, which can be used to produce energy by nuclear fusion. In the name of building a nuclear power plant which includes exploitation of nuclear materials, the US may turn the moon into a production site of nuclear weapons, he alleged.

Li Haidong, a professor at the Institute of International Relations of the China Foreign Affairs University alleged the US plan is against the international consensus on using outer space. As per the Moon Treaty, adopted by the United Nations General Assembly in 1979, the celestial bodies and the moon are “not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means”. Earlier this year, President Trump had proposed new rules, completely in contrast to the earlier agreement. Called ‘Artemis Accord’, this allows the use of lunar resources for commercial gain. The accord also focuses on establishing “safety zones” around landing sites, which could be interpreted as de facto ownership of areas of the moon, which is forbidden by the Outer Space Treaty.

The Outer Space Treaty was largely based on the ‘Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space’. It provides a basic framework for international space law.

Source: The Space Thinkers

What is this really all about? Profit? Prestige? The Idaho National Laboratory, which is eager to develop the lunar SMR prototype, sees this as an opportunity to emphasize “the United States’ global leadership in nuclear innovation,” the lab’s John Wagner told Newshour. With the ever-expanding crises on Earth, caused by the ravaging effects of climate change as well as the current pandemic, spending large amount of sums to stick reactors on the Moon or Mars is more than madness; it is morally irresponsible. NASA’s Anthony Calomino told Space News. “The surface of the moon provides us an opportunity to fabricate, test and flight qualify a space fission system,” he said. The Moon is seen as our launch pad to Mars. Now, it seems, it will also become our latest nuclear dustbin. If there is a meltdown, or a cascade of accidents among the cluster of small identical reactors there, all of which could suffer the same failure at the same time, it will become our next nuclear wasteland.

Infact, humanity is unconscious to the reality of how accustomed they are to the moon: tracking the moon’s cycle, building scary anecdotes about the full moon, monitoring the effect of its phases on tides and other phenomena. Nature arranged everything in an ideal way ensuring perfect balance on the Earth.I am happy to say “goodnight moon.” But I don’t want to say “goodbye.”

Hello Readers,

This article was written in collaboration with the marvelous Yashu Gupta. I would like to extend my deepest gratitude towards her for her awesome ideas and writing. Hoping on working again with her in the future. I hope you enjoyed this extremely informative article.

What would happen if you touched the cosmic vacuum?

noreply@blogger.com (Unknown) — Sat, 19 Dec 2020 15:01:00 +0000

On August 16, 1960, American pilot Joseph Kittinger set a record for the highest altitude jump in the world. A huge balloon filled with helium lifted the pilot to the height of 31,300m (102,800 feet). During his ascent, the pressurization for his right glove malfunctioned which caused his right hand to swell up to twice its normal size and Kittinger experienced immense pain. This incident occurred in the stratosphere not outer space .Imagine what would happen to an astronaut if they literally touched a vacuum in space.

Source: Ridddle

But let’s review the basics first to get a better understanding. The higher you are above the surface of the Earth, the lower is the atmospheric pressure. We are aware of the fact that the atmospheric pressure at the sea level is 1 atm.On the highest mountain on the Earth, Mount Everest, it amounts up to ⅓ atm. And about 93 kilometres ( 63,000 feet) above the Earth a terrible fate awaits for anyone without a spacesuit. So imagine if a maniac decided to test the effect of the cosmic vacuum on themself. Well, there is no going back once they are in extraterrestrial space and there are no hospitals or space ambulances in case of an emergency. But if our subject is not afraid then let's get started.

Our subject (let’s call them Bob) drops a glove. The first and powerful thing an astronaut would feel in an unpressurized spacesuit is enormous pressure that would act inside the muscles and skin. Human bodies are designed for life on the surface of the Earth and a layer of the atmosphere is constantly pressing upon ourselves. So why don't we die from one tonne of air pushing against our bodies? The answer is simple: the atmospheric pressure is balanced by the air inside our bodies.

Source: NASA

However,space is a vacuum, which means that any person unfortunate enough to find their self unshielded in such an environment will experience rapid internal decompression. Even if the external pressure in one of our limbs drops to zero then the balance would be unstable. Gases which usually dissolve in our blood will immediately turn into blisters and burst in the muscles and skin. Moreover, under these conditions the fluids in the tissues will also start evaporating. This would cause Bob’s (subject) arm to swell up and the bubbles of gas would block blood flow resulting in the feeling of numbness in Bob. Due to the lack of oxygen the subject’s hand would start turning blue. But, will this sudden pressure drop cause the hand to explode?

There is one specific case in history where a persons’ entire body came in contact with a vacuum accidentally yet the person survived. This is evidence to the fact that the human body is really strong. So it is unlikely if the sudden pressure drop of a spacesuit will result in an astronaut’s hand( even without a glove) to explode. But, tissue damage under these conditions would still be possible.Yet, this doesn’t mean that the threat of dying completely departs.

Deep sea divers are sometimes diagnosed with a disorder called decompression sickness. During deep sea diving, divers become pressurized by columns of water with the force of several atmospheres. If for some reason they suddenly rise to the surface their body doesn't have enough time to adjust to the pressure drop. With the sudden rise, the gases dissolved in the blood ,especially nitrogen, turn into bubbles. Visualize a bottle of soda when you open it . The liquid inside literally foams with a thousand of bubbles. Now, imagine something similar happened to the blood in your body. Symptoms of decompression sickness are unpleasant. They include: severe headache, muscle and joint pain and loss of vision.

Source: NASA

Let’s get back to Bob. The worst scenario now is that the air bubbles that appeared in our subject’s could get into the other parts of the body via the bloodstream like the heart. Such a condition can cause myocardial infarction commonly known as a heart attack. But we know that the most important organ of our body is the brain. If the air bubbles clot the blood vessels, bulk structures of the brain would be left without oxygen. When this happens, in a matter of minutes, a stroke can occur and possibly even death. However, since Bob only removed his blood he might be able to avoid this from happening. Damaged tissues and clogged vessels in his hand wouldn't cause gas bubbles to flow further through the body. Therefore, Bob should mainly expect pain in the hand and possibly treatment and long recovery period.

Now getting back to space because the experiment continues. What else could happen to Bob? The answer is bitter cold. Afterall, everyone knows that in space the temperature is close to absolute zero. However,events in space would unfold a little differently because Bob(our subject) would not only not freeze but also receive a severe sunburn. How is that possible? The temperature in outer space is extremely low i.e, -270.42°C ( -454.75°F). A spacesuit-less human just outside the space station would surely either boil alive or get turned into a popsicle in under a minute, right? However, you’re thinking of heat transfer on Earth.

Source: NASA

In space, there is no air, so heat can’t be transferred through conduction (direct contact between two objects) or convection (energy transfer through a fluid like water or air). The only viable means of heat transfer between two objects — in this case the human body and space — that you’re left with is radiation. Humans radiate heat at a rate of only 100 Watts, much like an incandescent light bulb. Given the sheer mass of the human body, it will take a long time before you freeze. Another danger is awaiting Bob in space - the most powerful solar radiation.

On Earth’s surface, the intensity of solar radiation averages to about 635 W/m2. However, in space there is no atmosphere to absorb light. Therefore, the sun shines much brighter there. It’s power in low Earth orbit reaches to 1,360 W/m2. Hence, the ultraviolet rays in space are extremely dangerous and will cause sunburn. Suppose Bob prepared himself for the assignment and brought sunscreen. Will it be enough to protect him from the burn? Unfortunately no because in addition to visible and ultraviolet light in the cosmos there is a lot of ionizing radiation and cosmic rays.

Now imagine how many charged, subatomic particles will be in the hands of our subject if he removes his glove. Even though, radiation rarely kills a person instantly. Most likely, our subject won't even feel those charged particles hitting their body. But, radiation damage is the cause of many illnesses so after returning to Earth Bob would run the danger of developing cancer or something worse. In short, a hand caught in a vacuum can be saved especially if the rest of the spacesuit remains airtight. However, it is possible that when you remove the glove air may escape the protective suit. In this case, the person would lose consciousness due to Hypoxia in under fifteen seconds and add to this the effects of decompression sickness. So if you ever find yourself in space then avoid taking off your glove.

Basics of Rocketry: The difference between Sea-Level and Vacuum versions of Rocket Engines

noreply@blogger.com (Arjun_Raf) — Thu, 17 Dec 2020 11:30:00 +0000

Hello there rocketeers! Today we are going to find the answer to one of the most asked questions in space tech forums - why Vacuum version of rocket engines are bigger than their sea-level counterpart?

If you are an ardent follower of rocket launches of agencies around the world, it is pretty sure that you may have at least come across the term - vacuum optimized engine. Threads about 'vacuum optimization' is not rare at all in rocketry forums with many giving convoluted answers which would be hard to understand for a layman. Don't you worry, in this article we explain the conundrum in detail for our readers out there.

Before we start off with the explanation, we need to take a trip down the theoretical part of what makes the rocket do what it is supposed to. While the rocket equation is a very important equation for rockets, there is another equally important equation which gives the 'thrust' developed by a rocket engine. Since the derivation is not under our scope for this article, we'll be leaving that part out.

Basic thrust equation of rocket

In the above equation, the thrust developed, F, is the sum of product of propellant mass flow rate (q) and velocity of exhaust gases (V_e) and product of pressure difference (P_e - P_a) and area of nozzle exit(A_e). While the bulk of the thrust developed from the engine is from the velocity of exhaust gases, for achieving maximum thrust from the engine, the pressure thrust term must be also considered.

Check the pressure thrust part of the equation, (P_e - P_a) x A_e. It is seen that the V_e and P_e are inversely proportional, i.e., when one increases, the other decreases. The main objective is to increase V_e as much as possible at the expense of pressure which is built up inside the combustion chamber.

OPTIMIZING EXPANSION

In a rocket engine, the fuel+oxidizer mixture is burnt inside the combustion chamber producing enormous amount of energy mainly in the form of pressure energy. For a rocket to achieve thrust, this pressure energy must be converted to kinetic energy by forcing out the exhaust gases out at very high speeds. This is achieved by using a converging-diverging nozzle.

A cross-sectional view of a standard rocket nozzle, Credit: NASA

Inside the converging section of the nozzle, the pressures would be very high with very low velocity. The gases travel down the throat, in here the gases approach sonic velocity (Mach 1) and in the divergent section, the gases starts to expand. In the divergent section, the gases expand until ambient pressure is reached at the exit. The diverging section is where pressure energy is converted to kinetic energy.

In rocketry, for maximum thrust, the pressure at the exit of the nozzle must be equal to the ambient pressure or P_e = P_a, which is called optimum expansion or correct expansion. Whether the expansion is optimum or not depends upon the geometry of the expansion nozzle of the engine, so it is obvious that sea-level and vacuum engines would have some differences.

DIFFERENCE BETWEEN ATMOSPHERIC AND VACUUM FIRING

When the engine is fired at sea-level, the ambient pressure P_a is atmospheric pressure. So, the gases exiting the nozzle must be expanded up to atmospheric pressure to achieve optimum expansion. However, when the rocket has entered space, the ambient pressure is nearly zero, which implies the gases must 'expand' more than it did while in atmosphere to achieve maximum thrust.

A clear example is the difference between SpaceX's sea-level Merlin engine and vacuum Merlin engine. The interesting thing is that both the engines, sea level and vacuum optimized has nearly the same chamber pressure! But the sea-level engine produces 845kN of thrust while the vacuum optimized produces 981 kN, a 16% percent increase in thrust.

Credit: EverydayAstronaut

The large size of the vacuum optimized nozzle is to allow the gases to approach very low pressure at the exit to produce maximum thrust. If a sea-level nozzle is used in vacuum, the pressure at the exit would be significantly high and the gases would continue to expand even after exiting the nozzle, which is not desirable. This condition where the gases are not expanded enough is called under-expansion.Likewise, there is also over-expansion, which occurs when the nozzle size is too large and the gases expand to pressures lower than ambient pressure. Both these condition are not desirable for optimum thrust.

Credit: aerospace.org

So, yeah, that's why the vacuum versions of engines have a significantly larger nozzle than its sea-level counterparts.

Autonomous systems: A model for space exploration missions

noreply@blogger.com (Unknown) — Mon, 14 Dec 2020 11:10:00 +0000

aerospace.org

What is Autonomy?

Autonomous systems are machines and systems that are capable of performing a series of operations where the sequence is determined by the outcome of the previous operation or by reference to external circumstances that are monitored and measured within the system itself. These incorporate artificial intelligence (AI) into the management and control of complex systems. Automated systems are independent of human operators though their management and control may be centralized or distributed. The basis of these autonomous and automated systems are defined through the system integrating physics. In addition, an understanding of each of the system functions, subsystems, and environments is necessary for AI decisions to be sound with regard to the system operations.

What is not Autonomy?

Autonomy is NOT artificial intelligence, but may use AI

• Machine learning (deep learning, reinforcement learning, etc.)

• Search, probabilistic methods, classification, etc.

Autonomy is NOT automation, but often relies on automation

• Most robotic space missions rely on automation

• Command sequencing (event, order, time triggered)

Autonomy is NOT only about making systems “adaptive”, “intelligent”, “smart”, or "uncrewed".

• Autonomy is about making systems self-directed & self-sufficient

• Systems can include humans as an integral element (human-system integration, human-autonomy teaming, etc.)

The Need of Autonomous systems

The space environment is harsh and remote for autonomous systems. Beyond the protection of the Earth’s atmosphere, man-made objects operating in space are surrounded by extremes of temperature and high energy radiation. Space weather disturbances to the near-Earth space environment resulting from solar activity adds significantly to the complexity of the space environment, and poses additional threats to space-based activity. We know from experience that space weather can degrade or even destroy spacecraft yet our understanding of and ability to predict the dynamic space environment is poor. Activity of spacecraft in orbit around other bodies (such as Earth) are complex and interactions that occur between space objects and their local dynamic space environment, known as astrodynamics are non-negligible and we need to look into this.

Space is also becoming increasingly congested. The risk of in-orbit collisions is growing and can ultimately limit our use of space. Inactive satellites and collisions are both contributors to a vast artificial space population. The Space Object Catalogue seeks to maintain accurate knowledge and its uncertainty of the orbit of each object in space, so that close approaches of space objects can be predicted and the probability of collisions can also be computed. Trusted Autonomy can be very important for handling such issues successfully. Also space is hostile to human life and therefore the ability to have close human supervision, management and operation of space systems is inefficient, costly and dangerous. This dictates extensive use of unmanned technologies, with the need for built-in autonomy ranging from simple fault detection and isolation functions for hardware protection through to full, goal driven autonomy, depending on the complexity and purpose of the mission.

nasa.gov

The Space Activity and missions

Deep space exploration missions to date have almost consisted of unmanned spacecraft missions. These include space probes that have flown past all planets in the Solar System (as in the case of the Voyager 1 and New Horizons spacecraft, have flown beyond Pluto),space probes that have been placed into orbits around planets or moons of planets, planetary landers on planets, moons, asteroids and the various robotic rovers currently active on the surface of Mars. For example, almost all remote sensing satellites automatically acquire images at predefined geographic locations and downlink them to Earth. Also In-orbit robotic capabilities are controlled by astronauts but few autonomous space systems, where the system makes decisions in order to achieve high level goals without human intervention, exist.

As described by the UK Robotics and Autonomous Systems Network, space robotics and autonomous systems will play a critical role in mankind’s ability to explore and operate in space, “by providing greater access beyond human spaceflight limitations in the harsh environment of space and by providing greater operational handling that extends astronauts capabilities”. Indeed, NASA’s Technology Roadmap for Robotics and Autonomous Systems has the goal to extend and enhance human reach into space, and our ability to manipulate assets and resources, to prepare planetary bodies for human arrival, support astronauts in space operations, and enhance mission operation efficiencies.

Autonomous systems can also reduce human workloads by managing routine activities requiring constant monitoring over long periods of time. In 1998, the Deep Space 1 mission, with Remote Agent architecture, provided the first operational use of artificial intelligence in space, including complete autonomous operation during which it responded to both simulated and real failures. Earth Observing 1, a remote sensing spacecraft launched in 2000, was able to employ autonomous acquisition and processing of science data. Mars Exploration Rovers which are able to autonomously plan paths to objectives while avoiding obstacles, and autonomously process captured images and what new observations should be made are also one of such examples. The implications including the congested space environment can also be solved through autonomous space traffic management systems or autonomous spacecraft collision avoidance capability.

link.springer.com

The current scenario

The ‘push’ for autonomous systems is coming from the involvement of the huge corporations and from the linking together of technology developments in connectivity, sensors and handling of big data. Market ‘pull’ is coming from a very wide range of applications where autonomy promises to do things that could not be done before, or to do existing operations more efficiently or safely. The development of such systems can significantly promote innovation in AI technologies including unmanned vehicles, unmanned aerial vehicles, service robots and space robots. Following are the areas of research and development in this field.

• Autonomous target selection for icy worlds, interior oceans, caves, pits, etc.

• New 3D sensors ( time-of-flight cameras, etc.) & high-performance computing .

• Observe dynamic & transient phenomena (weather etc.)

• Autonomous on-board decision making (planning, scheduling & execution).

• A distributed autonomy architecture (including coordination and collaboration) .

Many organizations are already striving to develop the next wave of trustworthy, cost-effective autonomous systems, and researchers are busy building powerful tools and methods for the development process. So we can conclude that this is an emerging field so we should contribute significantly in this through our determination and hardwork.

themanufacturer.com

The Ultimate Guide To Terraforming

noreply@blogger.com (Unknown) — Sun, 13 Dec 2020 11:08:00 +0000

Terraforming- the likeliness of that you have heard this word being thrown around before and probably in some science fiction movie or story is strong. In the past decades, the interest in space exploration has significantly increased. This renewed growth in curiosity has led to the issue of terraforming being addressed as a near future possibility. Obviously with Elon Musk’s plans about how humanity needs a “backup location” to survive, and space agencies like NASA and ESA considering the prospect of a long-term habitability on Mars or Venus or the Moon the concept of terraforming is not a fiction after all.

Credit: Metro-Goldwyn-Mayer

But of course now we are faced with countless questions like what does terraformation entail? What kind of Technology does it require? Do we already have access to that type of technology? What are the odds of it being a success? Answering any or all of these questions requires that we do a bit of digging. But first let’s understand the meaning of the term ‘Terraforming’.

In simple terms, Terraforming is the process of altering the combative conditions of a militant environment in order to make it more suitable for mankind. This might entail modifying the temperature, atmosphere, surface topography, ecology – or all of the above – in order to make a planet or moon more “Earth-like”.

Concept of Terraforming

In 1961, Carl Sagan proposed techniques to terraform Venus in his article published by the journal Science. He suggested planting algae in the atmosphere of Venus, this would convert the supplies of water, nitrogen and carbon dioxide in Venusian atmosphere to organic compounds and reduce Venus’ runaway greenhouse effect. In 1973, he published an article in the journal Icarus titled “Planetary Engineering on Mars“ in which he brought forth two scenarios for transforming Mars.

Credit: Kevin Gill

Later in 1976, NASA addressed the issue of planetary engineering officially in a study titled “On the Habitability of Mars: An Approach to Planetary Ecosynthesis“. This study concluded that the melting of the polar ice caps, and the introduction of greenhouse gases could all be used to create a warmer, oxygen and ozone-rich atmosphere. The first conference session on terraforming, then referred to as “Planetary Modeling”, was organized that same year. A NASA engineer and the author James Oberg organized a special session(the First Terraforming Colloquium) at the Tenth Lunar and Planetary Science Conference in March 1979, which is held annually in Houston, Texas.

In 1982, Planetologist Christopher McKay wrote a paper for the Journal of the British Interplanetary Society titled “ Terraforming Mars”, in which he proposed the prospect of a self-regulating Martian biosphere. This was the first time that the word terraforming was used in the title of a published article, and would henceforth become the preferred term.

In 2009, Kenneth Roy – an engineer with the US Department of Energy - presented his concept for a “Shell World” in a paper published with the Journal of British Interplanetary Sciences, titled “Shell Worlds – An Approach To Terraforming Moons, Small Planets and Plutoids“, his work explored the possibility of using a large ‘shell like structure’ to encase an external world. This would keep its atmosphere contained long enough for long-term processes to take place.

Credit: Karl Tate/space.com

There are also the concepts where a usable part of a planet is enclosed in a dome in order to transform its environment, which is known as “paraterraforming”. This concept, originally coined by British mathematician Richard L.S. Talyor in his 1992 publication Paraterraforming – The world house concept, could be used to terraform sections of several planets that are otherwise inhospitable, or cannot be altered in whole.

Habitable Sites

There are several habitable locations that are well suited for terraforming within our Solar system. Consider the fact that besides Earth, Venus and Mars also lie within the Sun’s Habitable Zone. However, Venus’ greenhouse effect and Mars’ lack of magnetic field , their atmospheres are either too thick and hot, or too thin and cold, to sustain life as we know it.

Credit: Ittiz/Wikimedia Commons

Other potential sites in the Solar System include some of the moons that orbit the gas giants. Several Jovian (i.e. in orbit of Jupiter) and Cronian (in orbit of Saturn) moons have an abundance of water ice, and scientists have speculated that if the surface temperatures were increased, viable atmospheres could be created through electrolysis and the introduction of buffer gases.

There is even speculation that Mercury and the Moon (or at least parts thereof) could be terraformed in order to be suitable for human settlement. In these cases, terraforming would require not only altering the surface, but perhaps also adjusting their rotation.

A Brief on Terraforming Mars

As we all know it ,Mars is the most popular destination when it comes to terraforming. The reasons for the same are very clear- ranging from its proximity to Earth, its similarities to Earth, and the fact that it once had an environment that was very similar to Earth’s – which included a thicker atmosphere and the presence of warm, flowing water on the surface. Lastly, it is currently believed that Mars may have additional sources of water beneath its surface.

Mars has a diurnal and seasonal cycle that are very close to what we experience here on Earth. A single day on Mars lasts 24 hours and 40 minutes, and owing to Mars' similarly tilted axis (25.19° compared to Earth’s 23°), Mars experiences seasonal changes that are very similar to Earth’s. Though a single season on Mars lasts roughly twice as long, the temperature variation that results is very similar – ±178 °C (320°F) compared to Earth’s ±160 °C (278°F).

Beyond these similarities, Mars would need to undergo several transformations in order for human beings to live on its surface. The atmosphere would need to be thickened drastically, and its composition would need to be changed. Currently, Mars’ atmosphere is composed of 96% carbon dioxide, 1.93% argon and 1.89% nitrogen, and the air pressure is equivalent to only 1% of Earth’s at sea level.

But the biggest challenge is that Mars lacks a magnetosphere, which means that its surface receives significantly more radiation than we are used to here on Earth. In addition, it is believed that Mars once had a magnetosphere, and that the disappearance of this magnetic field led to solar wind to strip away Mars’ atmosphere. This in turn is what led Mars to become the cold, desiccated place it is today.

Credit: Kevin Gill

Ultimately, in order for the planet to become habitable by human standards, it’s atmosphere would need to be significantly thickened and the planet significantly warmed. The composition of the atmosphere would need to change as well, from the current CO²-heavy mix to an nitrogen-oxygen balance of about 70/30. And above all, the atmosphere would need to be replenished every so often to compensate for loss.

Fortunately, all these shortcomings have a wide range of possible solutions. Mars’ atmosphere could be thickened and the planet warmed by bombarding its polar regions with meteors. These would cause the poles to melt, releasing their deposits of frozen carbon dioxide and water into the atmosphere and triggering a greenhouse effect. Introducing volatile elements like ammonia and methane would also help to thicken the atmosphere and trigger warming. Both could be mined from the icy moons of the outer Solar System, particularly from the moons of Ganymede, Callisto, and Titan. These could also be delivered to the surface via meteoric impacts.

After impacting on the surface, the ammonia ice would sublimate and break down into hydrogen and nitrogen – the hydrogen interacting with he CO² to form water and graphite, while the nitrogen acts as a buffer gas. In time, Mars’ ample supplies of water ice – which can be found not only in the poles but in vast subsurface deposits of permafrost – would all sublimate to form warm, flowing water. And with significantly increased air pressure and a warmer atmosphere, humans might be able to venture out onto the surface without the need for pressure suits.

However, the atmosphere will still need to be converted into something breathable. This will be far more time-consuming, as the process of converting the atmospheric CO² into oxygen gas will likely take centuries. Several possibilities have been suggested, which include converting the atmosphere through photosynthesis – either with cyanobacteria or Earth plants and lichens.Other suggestions include building orbital mirrors, which would be placed near the poles and direct sunlight onto the surface to trigger a cycle of warming by causing the polar ice caps to melt and release their CO² gas. Using dark dust from Phobos and Deimos to reduce the surface’s albedo, thus allowing it to absorb more sunlight, has also been suggested.Nonetheless, there are plenty of options for terraforming Mars. And many of them, if not being readily available, are at least on the table.

Women In Space: A history of pioneer ladies

noreply@blogger.com (Bibhunanda) — Sat, 12 Dec 2020 05:47:00 +0000

Women played very crucial role in the history of human space flight mission. Around 65 female astronaut travelled to space till now. Let’s know about some famous women pioneered to the journey of space exploration.

Valentina Tereshkova:

imdb.com

Valentina Tereshkova, created a history in the year 1963 and she was a soviet astronaut honoured for first and youngest woman on space.

Journey of women in space begins at that time though very often men are chosen significantly for a distinct space flight mission. On 16^th June 1963, She flew to space and spent almost 3 days in space in a solo space mission named Vostok 6.

Anyone who has spent any time in space will love it for the rest of their lives. I achieved my childhood dream of the sky.

Svetlana Savitskaya:
britannica.com

After 19 years of 1^st women Cosmonaut and aviator Svetlana Savitskaya became the second women to travel to space. She was also from Soviet Union. In the year 1982, she walked her flight to space and she spent around 19 days in space. On her 1984 mission, she became the first women to fly to space twice and the first lady to perform spacewalk.

Mae Jemison:

britannica.com

In 1956, Mae Jemison, an American engineer also former astronaut of NASA was the first black woman in space. As a space shuttle instructor, she was selected for the mission STS-47 for which she orbited Earth for around eight days (12-20 september) in 1992.

Don’t let anyone rob you of your imagination, your creativity or your curiosity. It’s your place in the world; it’s your life. Go on and do all you can with it, and make it the life you want to live.

Kalpana Chawala:

firstspot.com

Kalpana Chawala, first female astronaut of India. With dream of becoming an astronaut and with support of her father, she accordingly moved to U.S. and after completing education she joined NASA as a researcher. She also worked with spaceX and Blue Origin like companies and eventually selected for beginning her journey as an astronaut. She travelled to space to space two times.

Her first flight was became successful but on 1^st Feb 2003, during second flight due to explosion in space shuttle, she died with her six companion. STS-87 was her first space flight mission and the 28^th mission of Columbia; STS-107 was her second flight.

When you look at the stars and the galaxy, you feel that you are not just from any particular piece of land, but from the solar system.

Sally Ride:

nasa.gov

The first female of America to fly in space was Sally Ride. After completing her phd in physics, she simultaneously selected by NASA as an astronaut.

In 1978, she was selected in NASA Astronaut Group 8. She worked as mission specialists, capsule communicator. In 1983, she was a crew member for STS-7 space shuttle mission. She flew her second flight STS-41G in 1984 for which she spent 343 hours in space.

Our future lies with today’s kids and tomorrow’s space exploration.

Eileen Collins:

en.wikipedia.org

Eileen Collins, A NASA astronaut was the first woman pilot of space shuttle. In the year 1990, she was joined as a pilot in NASA, became a pilot in 1995 and in the year 1999, she became the first female commaner to command the space shuttle as a pilot. She was a commander of mission STS-93.

We want to explore. We are curious people. Look back over history, people have put their lives at stake to go out and explore….
We believe in what we are doing. Now it’s time to go.

Peggy Whitson:

nasa.gov

U.S. astronaut Peggy Whitson, was the first woman to command International Space Station. She has a record of reaching orbit as an oldest women astronaut. She has a record of spending more than 534 days in space.

The future of the world may well depend upon our desire to achieve and courage to explore.

Women like above famous personality broke all life barriers, follow their path believing in their dreams, finally achieved the success they want in life. They all contributed many observations and achievements in the era of space exploration and inspired everybody to believe and live the life we ever emagined!!

ISRO's desi GPS - NavIC gets IMO Recognition

noreply@blogger.com (Arjun_Raf) — Thu, 10 Dec 2020 08:30:00 +0000

India's own navigation system or as media likes to call it , the desi GPS, IRNSS or NavIC has received a huge impetus after it was recognized as a component of the World-Wide Radio Navigation System (WWRNS) by International Maritime Organization (IMO). The recognition was awarded in November, 2020, in IMO's 102nd meeting of Maritime Safety Committee. The recognition will allow sea-going vessels to use the service of NaVIC for navigation.

The recognition certificate as shared by ISRO, Credits: ISRO

Even though the system has received this boost, there is still a long way to go for the system to have operational competency with other navigation platforms available. This is raised by IMO itself in the 3rd and 4th points of the letter shared above.

IMO's statement is that IRNSS or NaVIC has not yet achieved operational accuracy requirements and they are suggesting with future corrections, it can be verified. This is particularly critical for vessels operating near ports since the traffic would be high in the locality and accuracy is paramount for ships operating near such areas. We could guess from this statement that the system still has some major works to be finished before it can be released as a potent navigational platform.

IRNSS was born out of USA's reluctance to share GPS data with India during the 1999 Kargil War. The Indian government saw the need for an independent navigation system, at least for the Indian sub-continent since positioning data from foreign controlled satellites won't be always guaranteed.

The IRNSS constellation started off with the launch of IRNSS - 1A on July 1st, 2013. Since then, a total of 8 satellites have been launched with the last launch being that of IRNSS - 1I on April 12th, 2018. The constellation was initially planned to be just 8 satellites, but latest news suggests that a total of 11 satellites would be set up in near future.

The program has also seen its fair share of eventualities over the course of 7 years since the first launch. In 2017, the first satellite of the constellation to be launched, IRNSS-1A was struck with a problem when its atomic clocks failed. This was similar to the problem faced by ESA's GALILEO navigation system, both having atomic clocks manufactured by the same company. Soon after, other atomic clocks in orbit with other satellites in the constellation started failing and ISRO has kickstarted a project to develop indigenous atomic clocks, which would be developed by ISRO's Space Applications Center (SAC).

Credit: ISRO

To replace the doomed IRNSS - 1A satellite, IRNSS - 1H was launched on August 31st, 2017 which too struck doom when the payload fairing failed to separate and the mission written off as unsuccessful.

Is Indian Space secured from terrorism and hackers?

noreply@blogger.com (Ashmita Deb) — Wed, 09 Dec 2020 12:28:00 +0000

"Terrorism"- this one word is enough to describe the history of frightening incidents which demolish the humanity. It has made new shifts in the age of A.I. which gave birth to Space terrorism. We must be aware of these new changes to face the challenges.

Accessing data through satellite
Credit: ORF

India is standing in a very geostrategic region which connects us to various other territories with diverse minds. Space weaponisation and space terrorism is an emerging field. Weaponisation and terrorism share a blurred line of differences. Weaponisation means to empower the space or any territory with weapons in the context of national security whereas terrorism means to use the space only for benefit of their plan attacks.

Credit: Marssociety

CASE STUDIES

In Syria and the Islamist countries, use the internet from a satellite in the form of a satellite dish. They use the internet in their private rooms or in media centres to communicate with the outer world. With the help of this, they can communicate from a remote area regarding their plan attacks even if the internet in that particular area is banned. The major providers are the European countries (Italy-Eutelsat, Cyprus-Avanti), which provide systems to get connected to the satellite internet for their work purpose. It has the advantage of having high-speed internet and disadvantage is it is very costly even for small packages. The companies which manufacture satellites and put them into orbit can easily trace the individuals who are using it and also what kind of information they are using. It takes only one click in the web portal OSS to switch it off. It is a huge industry and it makes huge profits. It is not easy to make this industry of terrorism shut down. This is the daily need of terrorist militia, so they pay a huge amount for it.

The government of every country must take united steps to make terrorism stop by monitoring every satellite stations and what data are being shared from these satellites. These must be monitored by a non-state actor and in a neutral way.

Credit:ZipNews

Space Tech in Terrorism

Satellites which help us in every sphere but can be dangerous for us. Satellites are keeping an eye on us. Now, just imagine if someone is keeping an eye on us for every 24 hours. It is a violation of our privacy, Isn't it? We have some kind of legal rights for the protection of privacy, prevention of surveillance and protection of national interest by not too detailed and no real-time image. Let's go further to explore more in space technology usages for terrorism.

The legal rights we have for space crimes are threadbare. We must look into the legal procedures for the prevention of crime. There must be some legalities which would be applicable when someone has committed some crimes using satellites but, we must be capable of stopping that before it happens.

China has some histories of hacking NASA computers and collecting data regarding the Deep Space Network which made the relationship between the USA and China bitter. India is a country whose foreign policy possesses a friendly approach towards its neighbouring states. China being our neighbour state has maintained an enemy relationship which may turn to adverse as China is much more proficient in A.I. and IoT than India. China believes more data makes A.I. more efficient, so they have used A.I. in every platform including education, technology, space, manufacturing, business, health, etc. China is also planning to make its situation which is a huge risk for countries like India, Japan, USA, Taiwan, and South Korea. There is a huge risk of placing weapons in a space station to destroy earth-based weapons or any satellites. Where China is heading towards the 6G, India is still lagging on 4G, which must be looked into.

Satellite Cloud Computing is also a facility which is very helpful for the astronauts. This helps to store data like high-resolution images (e.g.- Google Earth) and any sensitive information and process those data in any other projects through the use of A.I. This facility also can be used for terrorist activities. This facility easily provides access to data from anywhere in the space which helps to trace any point of Earth or target anyone. There is even risk of hacking personal data from personal devices like fingerprints, passwords through the use of satellites. We can use the GPS technology for Google Maps to trace the real estate property or to find the location of our destination. This is a cool thing to trace another person's location in dual travelling but have you ever thought it can be risky also. It puts a huge risk in your privacy. Your geo-location can be traced from space for any evil purpose.

Space legal organisations must formulate their policies to provide high technology but also to save Earth from these evils. It cannot be done solely. It must be done with the amalgamation of science and policy with the help of the government of every country with their private sectors.

Conjunction of 'Giants' — The Complete Picture

noreply@blogger.com (Sagnik Chatterjee) — Mon, 07 Dec 2020 16:43:00 +0000

The two gas giants - Saturn and Jupiter are coming closer to each other!

Except that they aren't actually 'coming closer' to one another.

It's just that when viewed from Earth at the proper instant, these one of these heavenly bodies, both moderately bright dots in the night sky, will be in proximity to the other.

Artist's impression (Credit: Allure)

Astro-folks, the best part is yet to come. This particular celestial event, termed as a inter-planetary conjunction or simply, conjunction, since 2005, there has 279 recorded conjunctions and this is the 280th one, but what makes it so special? To answer that, we need to have a quick history check.

Year 1226

The Mongol emperor Genghis Khan has been successful in uniting the nomadic tribes of Northeast Asia and is now expanding his territory far and wide. Khan, all of a sudden, calls off his military campaign in West China and withdraws his armies to Mongolia.

Historians speculate that this decision was influenced by astrological interpretation of a celestial event. Turns out that between November 20, 1226 and January 28, 1227, there have been five conjunctions!

The five conjunctions in detail were published in a paper by A. Vibert Douglas of the Kingston Centre under the title Historical Significance of Five Conjunctions, 1226-27:

The first of the five conjunctions involved Mars and Saturn, with Mars moving eastward more rapidly than Saturn and passing it about November 20 (1226) when Jupiter was some 5° further east.

The second conjunction occurred when Mars came into alignment with Jupiter at the end of November.

The third involved Venus and Saturn about December 18 with Venus moving rapidly eastward.

By December 27, the fourth conjunction took place when Venus passed Jupiter.

The fifth occurred a month later about January 28 when Venus overtook Mars. By that date, Saturn had already passed the Sun into the pre-dawn sky and Jupiter was to follow suit in early February.

All of these happened within a span of two months. Out of the five interplanetary conjunctions, the one with Jupiter and Saturn occurs every twenty years, but only a handful of them have had their impact on the lives of people.

Year 1325

The Jupiter-Saturn conjunction of 1325 influences the Italian poet, Dante Alighieri to such an extent that he uses the celestial event in his literary work, The Divine Comedy, to indicate a powerful leader who would reform Christianity.

Year 1345

This year's conjunction takes place on March 21, 1345, but from various literary works it seems evident that 1345's event was predicted ominous.

From 1347-1351, about 25 million people dies from bubonic plague and the astrologers 'prophecy' is taken into account.

Another plague occurred in 1373, the same year a Saturn-Mars conjunction happened, astrologers used the 1345 event as a reference.

Year 1623

It has been fifteen years since the monumental invention of the telescope by the Italian astronomer, physicist and engineer, Galileo Galilei based on the designs of the Dutch eyeglass maker, Hans Lippershey. However, this conjunction is quite impossible to view from Earth as it is 13 degrees away from the Sun.

Composite image of the predicted conjunction. (Credit: BBC Sky)

Roughly after 400 years, on December 21, 2020 the two gas giants will again be aligned close to each other and this one will be the closest encounter since 1226. Even though they may appear close, they will actually be separated by about 450 million miles!

Social distancing on point.

Celestial Events-December 2020

noreply@blogger.com (Bibhunanda) — Fri, 04 Dec 2020 05:02:00 +0000

We all are now entering the last phase of the year 2020. This year passed with many circumstances, many achievements with some different taste differ from previous one. So many things changed if we compare the end with the beginning of the year. Even the position of different objects, moving celestial bodies in space are changed from their original place. The year 2020 has been full of different exciting celestial events that we already watched. Let’s discover some of these amazing phenomena of December; last journey of the year!!

-->Geminids meteor shower- 13,14 december

-->Total solar eclipse, New moon- 14 december

-->Ursid meteors- 21,22 december

-->Winter solstice- 21 december

-->Great conjunction of Jupiter and Saturn- 21 december

-->Full moon- 30 december

GEMINIDS METEOR SHOWER:

Meteor shower is such an exciting event to watch. Geminids shower is the most important and spectacular meteor shower appear in the sky. Geminids meteor shower wil visible on 13^th December and upto early morning of 14^th December. But one can see this from 4-17 December for around two weeks but best to watch between 13 &14^th of the month. We can see around 120-130 meteors per hour on these days when they are active on their peak.

Geminids Meteor Shower (Credit- earthsky.org)

TOTAL SOLAR ECLIPSE:

On 14th December, the moon will be in between the sun and the earth and moon covers the total region of the sun occuring total solar eclipse. It will not appear all over the world. Only people belongs to the region of southern hemisphere like some part of South America, Chile, Argentina and the duration of the eclipse will be very short approx 2-3 minutes. This phenomena happens only when new moon appears between sun and earth. The next total solar eclipse will occur on 4 December 2021 with a long duration.

Observed region(Credit-skyandtelescope.org)

URSID METEORS:

Possible Ursid Meteor Shower showing along with Constellation
(Source-timesanddate.com)

Check Out-Celestial events of November 2020

WINTER SOLSTICE:

This is the phenomena occur twice in a year for each hemisphere. It happens when one pole of the earth tilt away from the sun. As a result this is the day of shortest day time and logest night. This is also called hibernal or hiemal soltice. Often it also said as mid-winter.

This phenomena occurs on 21^st December of the year; the day of shortest day and longest night.

CONJUNCTION:- Jupiter & Saturn

This is one of the rare astronomy event of the year. In this event, the planets Jupiter and Saturn will come very close to each other that it will be difficult for watchers to compare the difference. The two planets appear as double planet called great conjunction will visible on 21st December.

Conjunction is the event occurs when two celestial objects make a closer approach to each other and appear as a single bright object in the night sky. The two planets will be present on the top of one another with only 0.1° apart.

Conjunction of Saturn and Jupiter occur in every 20 years. Last "great conjunction" viewed was on 28th May 2000. But the next Saturn-Jupiter conjunction will be on 2080 after 60 years.

Showing possible planet allignment "Great Conjunction"
( Credit-timesanddate.com)

FULL MOON

This is the day in which Moon will be completely illuminated and clearly visible on the dark night sky. On the last day of the year; 30 December, Full moon will appear. We can observe it on late night of December 29 to early time of 30 December. This is the 13th and final full moon of the year often we called it as cold moon.

The full cold moon also called long night moon as it appears on the longest night and will be clearly visible on the darkest night sky of the year.

Phases of Moon in Dec (Credit- NASA)

This is all about the important celestial events of December. Mark your calender and observe the events described. Stay connected for similar exciting events of the upcoming year 2021!!

How much pollution does a rocket launch creates?

noreply@blogger.com (Arjun_Raf) — Thu, 03 Dec 2020 11:30:00 +0000

The title of this article is a question that has been lingering in my mind for quite some time. I have always wondered, the thick smoke spewed out by monstrous rocket machines launching into the sky should produce some serious pollution right? Moreover, why isn't people not talking enough about the pollution made by the launches?

Come on, this clearly doesn't look good for the atmosphere
Credit: PTI/ISRO

Up until recently, the pollution caused by rocket launches were sidelined for the huge technology advancement space industry has gifted humankind. However, as the risks of climate change gets more profound day-by-day, and rocket launches getting more frequent than ever before sidelining its impacts would be perilous. It is certain and obvious that the launch frequency of rockets is not going to reduce considering how space-based startups are budding across the globe. Low-cost satellite technology would directly result in frequent rocket launches and this leads to more emissions.

POLLUTANTS PRODUCED BY A ROCKET

A rocket can produce a wide variety of pollutants which depends on the types of fuel used. In the following list, we will take a peek into some of the common by-products of combustion from a rocket engine.

Liquid Hydrogen / Liquid Oxygen (Hydrolox) - Water vapor and Oxides of Nitrogen. The oxides of nitrogen are not the direct by-products of the combustion but forms due to the interaction between the hot exhaust with atmospheric nitrogen.

Delta - IV Heavy lifting off using its RS-68A engines
Credit: WikimediaCommons
RP-1 / Liquid Oxygen (Kerolox) - Water vapor, Oxides of Carbon, Oxides of Nitrogen, Carbon soot, trace amounts of Sulfur compunds.
Solid Propellants - These are one of the most polluting fuels used in the sector. Exhaust contains Oxides of Carbon, Oxides of Nitrogen, Sulfurous compounds, Aluminum Oxide, Hydrogen Chloride etc.
Hypergolics - Hypergolics are fuels which combust spontaneously when the fuel and oxidizer come in contact. By-products include Oxides of Carbon, Carbon soot, Oxides of Nitrogen and Sulfurous compounds. The most famous example of hypergolics being used is in the Ascent stage of the Lunar Module for Apollo missions. In the video below you can see the Ascent stage escaping the lunar surface which was powered by hypergolic fuels.

A DIFFERENT PERSPECTIVE

Let us consider the most powerful rocket in service right now - the SpaceX Falcon Heavy. The first stage of this mighty beast carries about 280 metric tons of liquid oxygen and 120 metric tons of RP1 (a highly refined form of kerosene). High school chemistry tells us that the combustion process of kerosene would release CO2 which as we now know is a massive contributor to global warming. So, a single Falcon Heavy launch could produce enough CO2 in a few minutes than a commuter car would produce in decades or even centuries.

The space sector was hit very badly due to the COVID19 pandemic in 2020, so let us see how man launches took place in 2019. The year saw a total of 102 launches of which 5 were failures. The number was 74 in 2010. 2021 would have even more launches as many of the launches scheduled for 2020 has been bumped to the next year. Our point is simple, the number of rocket launches is only going to inflate over the coming years. Which means increased emission due to rocket launches.

Popular Youtuber, Everyday Astronaut, who is very keen about anything about rockets has provided in his website some rough figures for the emission from some of the popular rockets used. In his website, he adds that as compared to the airline industry, the emissions produced by rockets are minuscule which is true. However, we are missing something.

Rocket Emissions
Credits: Everyday Astronaut

WHY ROCKET EMISSIONS MUST BE TAKEN SERIOUSLY?

The main argument as to why rocket emissions must be taken seriously is the lack of governmental regulation. Space agencies and launch providers are not obligated to keep their emissions low and there is no mechanism to check the same. Moreover, as the rocket traverses across the atmospheric layers, the emissions from the rocket could have a different effect on different layers which is not yet fully understood. It is quite strange to realize that we haven't yet given it much thought to think about our planet when we launch rockets into others.

Airline emissions are confined to the lower layers of the atmosphere of which a large portion is washed down to the Earth by precipitation. Rockets on the other hand spew out their exhaust higher up in the atmosphere which takes even longer to settle down. The soot from solid rocket boosters is found to have heated up the upper stratosphere which on a long term is detrimental to ozone depletion.

The problem was so concerning that the United Nations included ozone depletion due to rocket emission in their 2018 Quadrennial Ozone Depletion Assessment.

A study by the University of Colorado at Boulder estimated that global rocket launches only contribute to about 1% of the total ozone depletion but that was 10 years ago. With launches getting more frequent this figure could rise though marginally which is not really a cause of concern for now. But that shouldn't be a reason to stop us from improving how rockets are made - more emissions happen due to the manufacturing of rockets than the launch itself, investing in researching and developing cleaner rocket fuels which won't leave that much of a dent on an already dented environment.

Hence, it must be an important goal of space agencies and industries invested in the sector to seek out new technology to keep the negative impact low.

Space Debris is Perilous: Causes and Solutions

noreply@blogger.com (Ashmita Deb) — Wed, 02 Dec 2020 13:15:00 +0000

“The biggest contributor to the current space debris problem is explosions in orbit, caused by left-over energy-fuel and batteries – onboard spacecraft and rockets” – Holger Krag, Head of the ESA’s Space Safety programme. “Despite measures being in place for years to prevent this, we see no decline in the number of such events. Trends towards end-of-mission disposal are improving but at a slow pace”.

Showing space Debris in space.
Source: ESA

The term “Space Debris” is used for space junk which is inactive and dead. These space junks stay at graveyard orbit. It is moving in the Earth orbit in a very high speed which may anytime have a collision with the space active and important objects. This is a huge issue for the active satellites and the International Space Station. The space junk speed is 22,300 mph, which is higher than the bullet. It is created by the launching of space objects like satellites, rockets and various other space objects which every part is not reusable. Apart from that, China’s Anti-satellite test has made a huge space junk which was a huge point of criticism all over the world. Some space junks have been turned to dust which cannot collide but can be lethal. It is a kind of space pollution which is hazardous for future civilization. In one side the human civilization is planning to settle down in the space, Moon, Moon and Venus but at the same time, they are polluting the space by not taking proper precautions in launching and cleaning up space. This may affect the space the same as Earth got affected by the plastics. The scientists are working on it with various scientific methods which include the breaking down of the space junk into various pieces, bringing back the space junk to Earth in order to recycle or restructure them.

Tiny bits of dead satellite and rocket in Space
Source: Britannica

The matter of space debris has no inclusion in the space field before the launch of the Sputnik 1 in 1957. Still, it has not got mentioned in the researches and academics. Last year, the two big dead satellites collided, the International Space Station has collided with many small objects from the space and three times they avoided the collision with space objects. The term space debris first got its mentioned in 1960. The term "Space debris" took a long time to take its place on the global platform.

Low Earth Orbit (LEO) is an orbital yard where millions of pieces of space junk are flying which includes the painting of spacecraft and pieces of spacecraft, tiny parts of the rocket and various inactive satellites. Till now, we don’t have any international space laws for the cleaning up of the space debris. Space Debris is a challenge not only for the active satellites but also for the celestial objects, space environment, space natural resources and future space missions. The U.S. Department of Defense is tracking the space junk. They have tracked more than 90% of non-operational satellites which is 20,000 artificial satellites.

Earth is covered with space junk
Source: ESA

European Space Agency has signed $103 million contracts with a Swiss start-up named ClearSpace SA to make a giant space claw to grab the space junk. Their first focus is a retired Vespa payload adapter. The target year is 2025. They are also thinking of recycling them by refuelling them or updating their technology. The Senate has approved the Bill S. 4827 on November 18^th, 2020 which aims for Space Traffic Management. The Chairman of the Committee, Sen. Roger Wicker introduced this bill on October 21, 2020, and asked for $15 million for the fiscal year 2021. The bill aim is to set up Centres of Excellence for Space Situational Awareness in the world which shall have emulsification of science and policy. Further, it shall provide data related to space debris in order to track them. The powers of this bill have been shifted from the Defense Department to the Commerce Department. The approved bill has some changes from the proposed bill. The minor changes are SEC. 2 (1) removal of “growing commercial activity in space requires immediate action to address”, SEC. 2 (4) addition of “manage, process and disseminate” in spite of “provide”. The major change is the SEC. (5) in which the bill states the abilities and functions of the Space Commerce. The proposed amendment under Chapter 507 of the title 51 is amended. The Bill is still waiting to pass the Congress. The Bill will be named as “SPACE Act of 2020” or “Space Preservation and Conjunction Emergency Act of 2020”.

Space Debris is a huge issue for the Earth as well as Space. It is our duty to preserve the space with the help of advanced technology and law. There are various organisations and governments are thinking about this issue and they are taking necessary measures. The think tanks and researchers must focus on it with an aim to solve the issue.

Superconductivity at room temperature

noreply@blogger.com (Unknown) — Mon, 30 Nov 2020 14:19:00 +0000

energy.gov

At normal temperatures, all materials have some amount of electrical resistance. This means they resist the flow of electricity. Because of resistance, some energy is lost as heat when electrons move through the electronic devices. But there are some exceptions called superconducting materials. Superconductivity is a phenomenon where a charge moves through a material without resistance. This allows electrical energy to be transferred between two points with perfect efficiency, losing nothing to heat. Superconductivity is one of nature’s most intriguing quantum phenomena. It was discovered more than 100 years ago in mercury cooled to the temperature of liquid helium (about -268.9°C, only a few degrees above absolute zero).Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.

Wikipedia

The above video of the Meissner effect in a high-temperature superconductor (black pellet) with a NdFeB (neodymium magnet). Let us first understand the types of superconductors- High temperature superconductivity and Low temperature superconductivity. High-temperature superconductors are defined as materials that behave as superconductors at temperatures above 77 K (−196.2 °C). The majority of high-temperature superconductors are ceramic materials. A ceramic is hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing a nonmetallic mineral, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick. LTS stands for "low temperature superconductor," which typically refers to Nb-based alloys and A15 superconductors that were already in use prior to the discovery of "high temperature" copper-oxide superconductors in 1986.

Meissner effect, the expulsion of a magnetic field from the interior of a material that is in the process of becoming a superconductor, that is, losing its resistance to the flow of electrical currents when cooled below a certain temperature, called the transition temperature, usually close to absolute zero. The Meissner effect, a property of all superconductors, was discovered by the German physicists W. Meissner and R. Ochsenfeld in 1933. As a superconductor in a magnetic field is cooled to the temperature at which it abruptly loses electrical resistance, all or part of the magnetic field within the material is expelled.Some superconductors, called type I (tin and mercury), can be made to exhibit a complete Meissner effect by eliminating various chemical impurities and physical imperfections and by choosing proper geometrical shape and size. Other superconductors, called type II (vanadium and niobium) exhibit only a partial Meissner effect at intermediate magnetic-field strengths no matter what their geometrical shape or size.

SciELO

One hundred years ago, on April 8, 1911,Heike Kamerlingh Onnes and his staff atthe Leiden cryogenic laboratory were the firstto observe superconductivity. In a frozen mercury wire, contained in sevenU-shaped capillaries in series, electrical resistance suddenly seemed to vanish at 4.16 kelvin. In 1913, lead was found to superconduct at 7 K, and in 1941 niobium nitride was found to superconduct at 16 K. Great efforts have been devoted to finding out how and why superconductivity works; the important step occurred in 1933, when Meissner and Ochsenfeld discovered that superconductors expelled applied magnetic fields, a phenomenon which has come to be known as the Meissner effect. In 1935, Fritz and Heinz London showed that the Meissner effect was a consequence of the minimization of the electromagnetic free energy carried by superconducting current.

Sciencenews

After decades, room temperature superconductivity is achieved. Above pic shows crushed between two diamonds, a compound of hydrogen, sulfur, and carbon superconducts at room temperature. Scientists have created a mystery material that seems to conduct electricity without any resistance at temperatures of up to about 15 °C. That’s a new record for superconductivity, a phenomenon usually associated with very cold temperatures. The superconductor has one serious limitation, however: it survives only under extremely high pressures, approaching those at the centre of Earth, meaning that it will not have any immediate practical applications. Still, physicists hope it could pave the way for the development of zero-resistance materials that can function at lower pressures.

Superconductors have a number of technological applications, from magnetic resonance imaging machines to mobile-phone towers, and researchers are beginning to experiment with them in high-performance generators for wind turbines. But their usefulness is still limited by the need for bulky cryogenics. Cryogenics is the production and behavior of materials at very low temperatures. Ultra-cold temperatures change the chemical properties of materials, which provide an interesting area of study for researchers. These studies have lead to advances in not only our understanding of different materials, but the creation of entirely new technologies and industries. Common superconductors work at atmospheric pressures, but only if they are kept very cold. Even the copper oxide-based ceramic materials work only below 133 kelvin (−140 °C). Superconductors that work at room temperature could have a big technological impact, for example in electronics that run faster without overheating.

Halperin, John Evans Professor of Physics at Northwesterns explains that now, a superconductor is just like there is no resistance to the charge. Therefore, no heat is generated when the current moves through the conductor. This is a good thing, because we don’t lose any energy in just heating the wire.

Superconductors—special metals that can conduct electrical current with no loss of energy could one day have a great impact on the efficient transmission of power in the United States and around the world. They could also lead to great innovations in medical imaging, drug analysis, and even telecommunications. While limited amounts of superconductors are already being introduced into the grid, there is much work left to be done, especially in understanding how these compounds actually work and how they can be improved.

Colliding Galaxies and the aftermath

noreply@blogger.com (Unknown) — Sat, 28 Nov 2020 11:55:00 +0000

Today, galactic collisions are a common feature in our Universe. Astronomy now frequently simulate them on computers, which realistically simulate the physics involved – including gravitational forces, gas dissipation phenomena, star formation, and more. Astronomers have been familiar regarding this impending collision for some time. This is based on the direction and speed of our galaxy and Andromeda. But more importantly, when astronomers look out into the Universe, they see galaxy collisions happening on a regular basis. It can be considered as common knowledge that our own Milky Way is on a collision course with Andromeda, the closest spiral galaxy to our own. At some point during the next few billion years, our galaxy and Andromeda are going to come together with catastrophic consequences.

Source: Hubble/ESA

Stars will be displaced out of the galaxy, others will be destroyed as they crash into the merging supermassive black holes. And the delicate spiral structure of both galaxies will vanquish as they become a single, giant, elliptical galaxy. But as cataclysmic as this sounds, this sort of process is actually a natural part of galactic evolution. Galaxies are held together by mutual gravitational force and orbit around a common center. Interactions between galaxies is a quite common occurrence, especially between giant and satellite galaxies. This is often the cause of galaxies drifting too close to one another, to the point where the gravity of the satellite galaxy will attract one of the giant galaxy’s primary spiral arms.

In other instances, the path of the satellite galaxy may have caused it to intersect with the giant galaxy. Collisions may lead to mergers, assuming that neither galaxy has enough momentum to keep going after the collision has taken place. If one of the colliding galaxies is much larger than the other, it will remain largely intact and retain its shape, while the smaller galaxy will be stripped apart and become part of the larger galaxy.

These types of collisions have been witnessed in the past as it is believed that Andromeda has collided with at least one other galaxy. Several dwarf galaxies (such as the Sagittarius Dwarf Spheroidal Galaxy) are currently colliding with the Milky Way and merging with it. However,since the distribution of matter in galaxies is extremely tenuous , meaning that actual collisions between stars or planets is extremely unlikely.

Source: ESO/NASA/ESA

Edwin Hubble in 1929 revealed observational evidence which suggested that distant galaxies were moving away from the Milky Way. This led him to create Hubble’s Law, which states that a galaxy’s distance and velocity can be determined by measuring its redshift, a phenomena where an object’s light is shifted toward the red end of the spectrum when it is moving away. However, later when spectrographic measurements were performed on light coming from Andromeda showed that its light was shifted towards the blue end of the spectrum (blueshift). This indicated that unlike most galaxies that have been observed since the early 20th century, Andromeda is moving towards us.

It was the year 2012 when researchers determined that a collision between the Milky Way and the Andromeda Galaxy was sure to happen, based on Hubble data that tracked the motions of Andromeda from 2002 to 2010. Based on measurements of its blueshift, it is estimated that Andromeda is approaching our galaxy at a rate of about 110 km/second.At this rate, it will likely collide with the Milky Way in around 4 billion years. These studies also suggested that M33, the Triangulum Galaxy will participate in this event as well. In all likelihood, it will end up in orbit around the Milky Way and Andromeda, then collide with the merger remnant at a later date.

Source: NASA/ESA/J. Lotz, STSc

Usually, in galaxy collisions , large galaxies absorb smaller galaxies entirely, tearing them apart and incorporating their stars. But when the galaxies are similar in size – like the Milky Way and Andromeda – the close encounter destroys the spiral structure entirely. The two groups of stars eventually become a giant elliptical galaxy with no discernible spiral structure. Such collisions are most likely to trigger a small amount of star formation. When the galaxies collide, the collision causes vast clouds of hydrogen to collect and become compressed, which can possibly trigger a series of gravitational collapses. A galaxy collision also causes a galaxy to age prematurely, since much of its gas is converted into stars.

After this period of rampant star formation, galaxies run out of fuel. The youngest hottest stars detonate/explode as supernovae, and all that’s left are the older, cooler red stars with much longer lives. This is why giant elliptical galaxies, the results of galaxy collisions, have so many old red stars and very little active star formation.

Even Though, the Andromeda Galaxy contains about 1 trillion stars and the Milky Way contains about 300 billion, the chance of even two stars colliding is negligible because of the huge distances between them. However, both galaxies contain central supermassive black holes, which will converge near the center of the newly-formed galaxy. Furthermore, this black hole merger will cause a significant amount of orbital energy to be transferred to stars, which will be moved to higher orbits over the course of millions of years. When the two black holes come within a light year of one another, they will emit gravitational waves that will radiate further orbital energy, until they merge completely.

Gas that was taken up by the combined black hole could create a luminous quasar or an active nucleus to form at the center of the galaxy. And last, the effects of a black hole merger could also kick stars out of the larger galaxy, resulting in hypervelocity rogue stars that could even carry their planets with them.