Wonders of the Universe

10 Things You Need to Know About Mercury

noreply@blogger.com (ashish) — Mon, 04 May 2020 14:06:00 +0000

Mercury is the smallest planet in our solar system—only slightly larger than Earth’s Moon.
It is the closest planet to the Sun at a distance of about 36 million miles (58 million kilometers) or 0.39 AU.
One day on Mercury (the time it takes for Mercury to rotate or spin once with respect to the stars) takes 59 Earth days. One day-night cycle on Mercury takes 175.97 Earth days. Mercury makes a complete orbit around the Sun (a year in Mercury time) in just 88 Earth days.
Mercury is a rocky planet, also known as a terrestrial planet. Mercury has a solid, cratered surface, much like the Earth’s moon.
Mercury’s thin atmosphere, or exosphere, is composed mostly of oxygen (O2), sodium (Na), hydrogen (H2), helium (He), and potassium (K). Atoms that are blasted off the surface by the solar wind and micrometeoroid impacts create Mercury’s exosphere.
Mercury has no moons.
There are no rings around Mercury.
No evidence for life has been found on Mercury. Daytime Temperatures can reach 430 degrees Celsius (800 degrees Fahrenheit) and drop to -180 degrees Celsius (-290 degrees Fahrenheit) at night. It is unlikely life (as we know it) could survive on this planet.
Standing on Mercury’s surface at its closest approach to the Sun, our star would appear more than three times larger than it does on Earth.
The two spacecraft of ESA-JAXA’s BepiColombo are en route to Mercury. NASA’s Mariner 10 was the first mission to explore Mercury. NASA’s MESSENGER was the first to orbit the innermost planet.

Particles and Anti-particles (Explanation)

noreply@blogger.com (ashish) — Sat, 31 Dec 2016 05:24:00 +0000

Particles and anti-particles:

The electron and positron

Electron:

Symbol: e or e ⁻

For beta decay ß or ß⁻

Mass = 9.11 × 10⁻³¹ kg

Charge = -1.6 × 10⁻¹⁹ C

= - 1 (relative units )

Electron is the member particles of lepton Family . The electron has a lepton number 1. This is the basic facts of the electron.

Positron:

This is the another elementary particles.

Symbol: e⁺ or ß⁺

Mass = 9.11 × 10⁻³¹ kg

Charge = +1.6 × 10⁻¹⁹ C

= +1 (relative units )

Positron is also the member particles of lepton Family. The positron has a lepton number -1. This is the basic facts of the positron.

So if we compare the electron and positron they have got a same mass and the other properties are reversed. The positron is called the anti-particle of electron but not because they have opposite properties. for further understanding lets discuss annihilation.

Annihilation:

let suppose that an electron is moving left to right and positron is moving left to right what will happen if they meet or collide each other

⇒ ⇐

Electron ⦽ ⦽ Positron

They vanishes with giving radiation in the Form of gamma photon.

Gamma photons

we can say that the electron and positron 'annihilate'. And the process is called annihilation.

They destroy each other and their mass has turned into energy (two gamma photons). From this we knew that Particle and its corresponding anti-particle annihilate each other and produce energy:

Particle + Anti-particle ➨ Energy

In the form of equation we can express it as:

e ⁻ + e⁺ = 2𝛄

electron positron two gamma photon

It is very important process which helps to understand the nature of particles and anti-particles. And the opposite process of annihilation is pair production.

Pair production:

If a gamma photon passes through a nucleus it break downs into electron and positron.

This process so called pair production because it produces a pair particles and Anti-particles.
In this case energy has changed into Particles and anti-particles.

   Energy ➨  Particle + Anti-particle

And the equation will be:

       𝛄 =   e ⁻ + e⁺

A gamma photon turns into particle and anti-particle pair in this process. The photon must a minimum energy of 2 Mₑ C ² .
Where Mₑ is the mass of electron and positron and C is the velocity of light.
i.e

Mₑ C ²   +   Mₑ C ² =    2 Mₑ C ²
energy of electron    energy of positron energy of photon required for pair production

Hope that this has helped a little bit for understanding about particle and anti-particle.

Living Zone in the Milky way galaxy

noreply@blogger.com (ashish) — Sat, 24 Dec 2016 04:26:00 +0000

Our living planet Earth orbiting an Star Sun along with other Planet i.e our Solar System is nearly 26000 light years away from the center of our galaxy (milky way galaxy). According to one hypothesis we have a very exclusive location. There is one idea that only stars in a certain range of distances from the center of our galaxy are in so called galactic habitable zone that is able to having life in the planets around them. The overall range of galactic habitable zone extends from 13000 to 35000 light years from the center of milky way. The main part where we are ranges from 20000 to 29000 light years away from the core. In the early history of our solar system was mostly violent place. Many explosions, collisions and violent things happen at that time and formation of such a nice and calm place takes place. We know that our sun is at least second or third generation star because there are planets around it, things are made up of iron, carbons and other heavier elements. But the process that lead life to earth doesn't seems exists outside the zone(galactic habitable zone).

Figure: Range of galactic habitable zone of milky way

Closer to the edge of milky way fewer massive stars were exploded producing fewer heavy elements. Further out galaxy it doesn't have as many atoms like carbon, nitrogen, oxygen the atoms are so important for the chemistry of life. So the habitable zone of our galaxy cuts off the distance where there is no heavier atoms to make life. If the outer part of our galaxy is a bad neighborhood then the inner area is even worse. Back in the time we thought that we are at the center of milky way but at the center of milky way a sucking matter and light into it there is a Sagittarius A- Star , a Black hole nearly 14 million miles across with the mass 3.7 millions time that of our Sun. There are other region in the galaxy that are also probably not great for life because there is just so much radiation from near by really hot O type stars. O type stars are giants having mass 15 to 90 times that of sun and surface temperature 30000 to 50000 kelvin and throw out titanic amount of ultraviolet radiation. With these stars you don't worry about sun burn but extinction. Its not probably easy to survive in an environment where there is lots of O type stars. O type giants can destroy planets before they form.

Figure: O Type Stars

To be safe from the Radiation of O type stars we must be at least 10 light years away from it. It is possible that our kind of life can live in only galactic habitable zone. But Elsewhere there could be other kind of life that we called extreme living beings on the other hand they would call us extreme living beings.