Venus Transit

The Moon, Venus and Jupiter

2012-02-26T20:34:00.003+02:00

Today (26-Feb-2012) The Moon was between Venus and Jupiter. The distance between them is still large enough so we will not call this setup a conjunction but rather an alignment. Nonetheless, it was very nice to see all three celestial bodies close together (They will look much closer next month!)
The first photo still in twilight, Venus at the bottom and Jupiter at the top.

The moon, Venus and Jupiter

The second is just a closeup of the crescent moon

The Moon 4.5 Days old

And the third photo will show all three bodies again with some earthly background

The moon, Venus and Jupiter

New Moon

2012-02-23T20:51:00.001+02:00

Tonight (23 Feb 2012) It was the first opportunity to see the new moon of Adar. The Hebrew calendar is a lunar calendar and the beginning of each month is decided by the moon. For the last 1600 years the calendar is calculated but before that, it was necessary to see the new moon, and to testify about it. Today, it is just nice to see the new moon each month. This month it was quiet easy, but sometime it is a real challenge.
As a bonus Mercury was near the new moon, but very hard to see. You can see it easily in the photo tough. Mercury is below and to the left of the moon. Also look how noticeable is the Earth-shine, making us see the entire moon. Rays from the sun are reflected from Earth, to the entire near side of the moon and reflected back to US. For this reason we see the entire moon, and even some details.

Take a look at the video started from 17:38, just minutes after sunset and still in daylight. As it gets later, the moon sets, more lights are on in the far buildings. Finally the moon vanishes before it sets below the horizon. The video is from 17:38 until 19:00. I am sorry for the video degradation. If you know better ways to make a video out of many individual photos please share as comments, and I will remake it.

Carnival of Space

2012-02-21T08:56:00.000+02:00

The Carnival of Space is a community of interest blog carnival bringing together the best and brightest Astronomy & Space Blogs at a single point in space and time (commonly referred to as a web address) each week.

This week Carnival of space is hosted by The next big future and is full of astronomical news and articles.

Previous Carnival of space:

Week 237 was hosted by Universe Today

Week 236 - was hosted by Peter Lake at the AstroSwanny blog

ISS and Orion

2012-02-20T22:30:00.001+02:00

The ISS is the brightest unnatural objects in the skies, brighter even than Jupiter, and in rare occasions even from Venus. You can compere its brightness to the well known constellation of Orion. The photo is from 2008 and since than the ISS got bigger so it is even brighter!

The ISS and Orion

Additional ISS articles

How to see the ISS

ISS in Lyra

London bookshops

2012-02-20T21:54:00.005+02:00

Every time that I am in London (Which doesn't happen often enough) I spent some time at London's bookshops. There are plenty of bookshops in London with huge variety, on many subjects. Books exist on any subjects but I look first for interesting second hand astronomy books in bargain prices.

The largest shop in London (and maybe in the entire world) is Foyles located at the center of London and open till 22:00 or eve 23:00. There are books on any subject, but there are only new books there so the prices are high. I came there mostly to look.

Some of the astronomy book at Foyles

A huge bookshop with lots of second hands and bargain books is Waterstone. There are many small brancehs, but you need to go to the main branch at Gower street. You can spend some hours there browsing between new books, bargain books and second hand books

Astronomy shelves at Waterstone

In my last visit I stayed at Bloomsbury area which has many fine bookshops. most of them will give additional discount to students. Skoob is a great shop (which holds just a bit of the stock) with the books are arranged more or less by subjects, and like many second hand bookshops you need to check them one by one. I got there with some great books such as Spring it Forward: The Annual Madness of Daylight Saving Time which deals with the daylight saving time.

Not very far is Judd Books which does not have a huge selection of science book and yet I found Earthrise which deals with the first photos of Earth from space. Of course, the famous British library is nearby at Euston street. Seven floors with undergrounds warehouses and 14 Million books. Must visit. Just opposite it two interesting bookshops. In the first the maximum price is 2 pounds and the second has many other cheap books.

This is a very small selection. The Guardian newspaper has an article with a longer list, you would like to print it for your next trip to London. Enjoy your reading.

Visual Feedback

2012-02-16T22:38:00.001+02:00

A feedback is when the output of the process become its input. When giving feedback to someone we expect him to use the feedback and change something according to it. In the following example of visual feedback, a camera is photographing a TV screen which broadcast what the camera photographs. This create an infinite closed loop with very strange results. Notice the colors, the patterns, the repetitions, the multiple clocks changing one after another. I even manage to create a galaxy shaped figure after zooming and tilting the camera. It felts like being a choreograph .
Another known example of the feedback effect is when a microphone is too close to the speaker creating an audio loop which ends in a very loud noise. this is the reason I left only the visual channel and removed the audio channel. But the amplification exists in the visual film as well, as the center of the photo get whiter and whiter.

If you are a teacher, you can repeat this little experiment in class. The kids will love it for sure.

Earth from Space

2012-02-14T10:13:00.005+02:00

How the Earth looks from space? Until recent history no one could see the earth from space. Although it was known for many years that the earth is round, It was not possible to reach the requires heights to see it. Surprisingly you do not need to go far to see the curve of Earth. Twenty kilometers (14 Miles) upward will be enough, but regular airlines never reach this high, and only few army jet pilots ever reached so high.
In this page I will present many photos of Earth from space, and we will start with the newest two pictures of earth from space by NASA satellite Suomi NPP which was launched not long ago, and sent back these two picture of earth from space

Space from Earth - Americas. Credit:NASA

This photo can (and shall) be compared to the famous blue marble picture of Apollo 17. Personally I like the old soft photo, as the new photo seems to sharp and digital. Compare for yourself later at this article.

Space from Earth - Africa and Middle east . Credit:NASA

However, the more interesting photos are not from Low Earth Orbit, but from spaceship far far away on wither sides of the earth (Close to the Sun or at the edge of the solar system). Let's start with a recent photo.
Juno mission to Jupiter was launched at August 5th 2011, Just 3 weeks after the launch, Juno turned back and photographed Earth and the moon. While it is a simple photo of lots of black and two dots, this photo is very interesting. It is clearly seen that the moon is darker than Earth (Check the article about the moon brightness). Earth is covered with clouds and water which are more reflective than the dark soil of the moon. Also, it is very easy to compare the size of the Earth and the moon. If all you see in the pictures are two dots on a black background, please think again.

Earth and Moon from space. Credit: NASA

One of the most famous pictures of earth from space is from Apollo 8 mission. The astronauts of this mission were the first to saw the far side of the Moon with their own eyes, and they submitted the famous "Earthrise" photo. Before that, and on the way to the moon they photographed the Earth. It was the first time that the whole earth was photographed from space. The astronaut who photographed it was probably Bill (William) Anders, who flight to space only in this mission

First picture of the whole earth - Apollo 8 Credit: NASA

This is the less famous Earthrise photo, just in the moment of rising.

Earth-rise - Apollo 8 Credit: NASA

And this is the more famous photo. Judge for yourself which you like more.

Earthrise - Apollo 8 Credit: NASA

However, Apollo 8 was not the first to photograph Earthrise, an unmanned mission, Luna orbiter, did it in 1966, In black and White poor resolution.

The first earthrise photo. LUNA ORBITER. Credit: NASA

As you probably notice, Earth has phases just like the moon, depending on their angle from the sun. the first photo of the Full earth was captured by the last of Apollo missions, Apollo 17, and was nicknamed "The blue marble"

The full earth from space - The Blue Marble - Apollo 17. Credit: NASA

During 2003, Mars was quite close to Earth (Just 55 Million km). It was a great opportunity to observe Mars, but it was also a chance to photo the Earth from Mars. Mars Global Surveyor took this amazing photo of the Earth and the Moon.


The Earth and the Moon from Mars. Credit: JPL MARS GLOBAL SURVEYOR NASA

Another very famous photo is the "pale blue dot". It is an amazing photo because it give you proportions about us, the earth and the size of the universe. Our planet is merely one pixel in this photo taken by Voyager 1 from 6.4 Billion km (4 Billion miles).

Earth from Saturn! The earth is a pale blue dot in one of the white stripes (at the right side of the photo). Taken by Voyager 1. Credit: NASA.

Cassini is orbiting Saturn sending amazing pictures day after day. This is a photo showing Earth through the rings of Saturn. Please enlarge the photo and see Earth as a little dot at the left side of the rings.

The earth through Saturn rings. Cassini. Credit: NASA

Next photos are from the Rosetta which is on its way to visit some asteroids in 2014. Its trajectory was designed to save energy and it included an approach to earth, on which the following sequence was taken.

Earth from Rosetta. Credit: ESA

The last photo is from Mercury. Messenger mission took this photo in August 2012 from 183 Million km (115 Million miles) and capture The Earth and the moon as a double star (Binary star) in the sky.

Earth and moon photographed by MESSENGER. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Moon Perigee

2012-02-12T09:21:00.001+02:00

Last night (11-Feb-2012) the moon was at perigee, which is the nearest point in its orbit to Earth. The distance was about 367,000 Km. The point of greatest distance is called apogee and it was more or less 402,00Km this month. The perigee and apogee points' distances change each month and the minimal Perigee is 356,000 Km while the maximal apogee is 406,000Km. The cause for the distance difference is the moon orbit which is not circle but, like all other orbs, elliptical.
This distance's difference make the moon looks slightly bigger in its perigee. However it is very hard to notice this difference with the naked eye. The perigee and apogee point are in different moon phases, and there is no easy way to compare them, but taking photos and put them side by side.

Even that is not so simple. The moon is in different phase, and in different angle. The best option is to wait until a full moon apogee and a full moon perigee. Patience is needed but the result will be better as demonstrated by Anthony Ayiomamitis photo which shows the difference very well.

Here are two photos from this month. The moon at perigee (the right photo) and the moon 10 days before it (A little after its apogee). Can you see the difference? Try and calculate it and see what are the results. Take into account the fact that when the moon is low in the skies it is a little further (Add some of the radii of the Earth) to the distance. This difference can be about 1-1.5%

Moon at perigee and apogee. try to compare the size

During 2012 the moon will be full at perigee on May 6 2012. The moon will be exactly full on its minimal distance of only 356953 Km and in apogee on 28th of November (406364Km). These dates are the best to take photos and compare the moon size.

Astronomy and Poetry

2012-02-03T11:26:00.000+02:00

What are the relationships between poetry and astronomy? Both are very ancient, from the dawn of the civilization, and seem to be very different. Astronomy is very scientific while poetry is about expressing feelings. Harvard university hosts a series of art lectures every summer. In 1967, Jorge Luis Borges was invited to give 6 lectures. The lectures were later forgotten for a long time, but eventually they were found and published in an audio book and as a regular book whose name is "This craft of verse".

The citation which is related to our topic appears at the beginning of the book:

"Whenever I have dipped into books of aesthetics, I have had an uncomfortable feeling that I was reading the works of astronomers who never looked at the stars."

Borges might have referred to this cartoon, showing 3 astronomers debate which one of them looks the least at the skies.
The physician Richard Feynman however has a very different attitude:

"What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?"

However many poems and songs are about stars, and most astronomers and astrophysicist take a look at the stars and enjoy this.

Lets start with Space Oddity, the famous hit by David Bowie. There are lots of cover versions for this song.

The following song is in Hebrew, but I am adding a short translation of my own, even if you do not speak Hebrew you will enjoy the tune and identify some of the names. You can also try and Google translate the following page

Milky way Ballad
Venus send a smile to Jupiter

Hey Jupiter, lets go out

A cappuccino cup in the Milky way

And drop by Cassiopeia

Grab the dipper, little or big

This night is terrific

It's quite a bit, Jupiter and Venus alone

Going out hand in hand

hand in hand in the heavens...

Lets jump for an hour to the north star

With a light breeze blowing

Just don't be like Plato

Those I do not like

Without a notice, on the tail of a comet,

we will sit for a moment

It's quite a bit...

Jupiter and Venus going higher

The stars wink to them

And Orion said without doubts

What a couple

And only Mars become jealousy red

She will leave him soon in the future...

Let's continue...

Robert Burnham was a professional astronomer and his work "Burnham's celestial Handbook" (BCH) is a must be in every astronomy library. His handbook (3 large volumes with more than 1000 pages) is a result of thousands of hours of work prior to the era of digital photography. And although the photos look old, and many amateurs get better results today, the books are still valuable with tons of information. Burnham's story is tragic, and mentioning his work is important. An important part of his books were the poems he wrote between the chapters. There are people who bought the books only for the poems. If you do not own a copy of the BCH, get one today (All 3 volumes).

Another good example would be the poet Robert Frost, with his poem Canis Major (The greater dog).

Canis Major

by Robert Frost

The great Overdog
That heavenly beast
With a star in one eye
Gives a leap in the east.

He dances upright
All the way to the west
And never once drops
On his forefeet to rest.

I'm a poor underdog,
But to-night I will bark
With the great Overdog
That romps through the dark.

And for dessert listen to this one: 'Drops of Jupiter" by Train.

So it seems that both Borges and Feynman were wrong, and astronomy and poetry go together hand in hand at least as Jupiter and Venus.

I am sure that there are plenty more poems and songs. Please add your favorites (to the comments area).

What is the size of Mars

2012-02-03T09:22:00.000+02:00

What is the size of Mars? How big is Mars? The Radius of Mars is 3,389.5 km (About half of the radius of the Earth). Its circumference is 21,344 km (Not a big surprise, this is also about half of the circumference of the Earth). The volume of Mars is 1.63116 X 10¹¹ km³ and the mass of Mars is 6.4169 x 10²³ kg.
Although Mars is smaller than Earth its surface area (38% of earth) Is Almost identical to earth LAND space (Since there are no oceans on Mars). A common hoax is about the moon and Mars being equal in size. The hoax started back in 2003 when Mars was in opposition to earth (Minimal distance) of about 55 Million KM. When Mars was in conjunction with the moon (A planet-moon conjunctions occurs once in a month), the message was that looking at Mars through75X magnification telescope will results in a size similar to a moon. While this is more or less correct, the hoax removed the telescope and the magnification leading people to think that Mars will be as big as the moon to the naked eye. This is of course a complete rubbish. Also the year 2003 was left out and that hoax continued for several years although Mars was not in opposition any more.

To kill the Hoax completely look at my own photo of Mars and the moon from 24-Dec-2007. There was no occulation (The moon did not cover Mars), but they were extremely close to each other. Mars red color is quite distinctive. You might be needed to enlarge the photo to see the small disc (It is clear that this is a disc and not a dot of a star) of Mars just under the Moon. Look closely. It is there. Mars was not as close as 55Million KM, but still the difference in size is huge. I took the photo in the early morning. Notice the nice flock of birds to the left.

Mars size compared to the moon

Sunspots

2012-02-03T09:14:00.001+02:00

Sunspots are regions on the sun on which the surface temperature is slightly lower. These regions emit less visible energy and from earth they look as dark spots. When looking at the sun with proper eye protection (glasses which are suitable for solar eclipse) the spots are clearly seen.

Warning: Looking directly at the sun, or photographing it without protection is dangerous and can cause permanent eye damage.

This article focuses on how to photograph sunspots. I've used a regular camera with 35X zoom and a special sun-blocking filter which blocks 99.99% of the sun rays (and also blocks UV and IR radiation). Photographing sunspots requires using a dedicated filter, it is not possible to improvise and use for example an exposed films for this purpose!

The spots can be seen easily. Looking through a telescope (again, a proper and dedicated filter is a must, using a telescope focuses the sun's energy into a single spot and using a non-proper filter will lead to immediate and permanent damage to your eye) will show even finer details, while looking through a special solar telescope will show details on the sun limb as well.

Sunspot

Both pictures show the same sunspots (sunspots are officially numbered and these two are 1203 and 1204 in case you wonder). The first photo was taken in the morning and the second just before sunset, and you can see that the location of the sunspots is very different. Why is this? It is not due to the daily movement of the sun (actually it is the earth which moves). It is also not due to the rotation of the sun around its axis (the sun rotates around its axis, and this rotation changes the location of the spots, however, the change is visible after a day or two and not just after several hours). The reason is simply the rotation of earth around its axis. To further explain this, look below at the same photos as above, only now I have drawn in the sun's axis. You will see that the spots are in the same place, relative to the axis, and what has changed is the angle at which we, on earth, observe the sun.

Same sunspots in Sunrise (right) and Sunset (left)

To summarize the issue, please watch the following video.

Albedo effect on the moon's brightness

2012-02-03T09:11:00.000+02:00

A full moon is very bright. So bright that you can read a book by its light. The moon the day before or after is almost as bright, at least it seems to be perfectly round and only a fraction of a percent is not lit, so how much can the brightness change? Actually a lot. Similarly, half moon, is not half the brightness of a full moon but much much less. We will see how the albedo effect influence the moon brightness over a period of a lunar month.

We will present the graph first, and then try to understand the reason for this strange phenomenon, which seems to defy logic.

The changes in the moon brightness during a single lunar month. Notice the big daily differences.

First, lets give some explanations on the measurement of magnitudes of stars. Brightness of stars is measured in logarithmic scale. Any change of 5 units in the magnitude is a 100-fold change in brightness. The lower the magnitude, the higher the brightness of the star. One magnitude unit represents a difference of about 2.5 times. As a reference star, Vega's magnitude is defined as zero. The magnitude of the sun is -26. The magnitude of the full moon is -12.7, much less than the sun but still the second brightest object in the sky.

The graph above shows the brightness of the moon in percent from its peak (100%). Please note, that the actual peak is not reached every month, since it depends on the moon's distance from Earth (the moon is a little brighter when it is closer to earth), but the surprise is the curvature of the graph. You can zoom into the graph and see how even the day before full moon, the brightness is only 75%, three days before full moon the brightness is half (While to the eye the circle of the moon looks nearly perfect as more than 90% of the moon is illuminated). The brightness of the half moon is only eight percent of the full moon, and the brightness measured at the beginning of a lunar month is less than a promil of a percent.

Why does this happen? The difference in brightness is due to several reasons. One intuitive. The less the phase of the moon, its brightness decreases. For example, for a half moon, this reason explains half of the decline (but not the other 85% of the decline).

The moon, like everything, has an Albedo. Albedo means the amount of light which is reflected from an object. The Albedo of the moon on average is 0.12 meaning that it returns only 12% from the light that it gets from the sun (this is relatively a low Albedo compared to other planets). But even this little reflection is made only when the moon is lit directly, what happens in the middle of the month. Mid-month light hits the moon at an angle and some of the light does not come to us, in addition to the lunar surface is not smooth but very rough. When the light comes to the moon at an angle (however minor), many areas of the moon surface are not lit and thus, do not reflect light at all. When the angle increases, the percentage of these parts increases, and the moon returns less and less light, resulting in overall decrease of the brightness .

Even when the moon is full, its brightness does not reach a peak (even at maximum closeness to earth). There's always an angle between us and the moon (the moon is not on the same plane as the sun and Earth) and when there is no angle and the moon can indeed return 100% of the light, the Moon will be the shadow of the Earth, we will experience a marvelous full lunar eclipse, and we will not observe the moon at all.

If you have a camera that allows you to control the setup you can test the moon brightness for yourself . Set the camera to measure light from the middle only (Spot). In this way the camera measures light only from the moon (of course put the moon in the middle of the frame). Set the aperture to be fixed (on 5.6 for example) and the ISO (on 100) and let the camera adjust the speed according to the amount of light exposure. Compare the exposure data of a half moon to a full moon over several nights and observe the differences. Full moon exposure time will be the shortest. Please note that the measurement of light must be of the same specific spot on the moon. Even the moon itself has brighter and darker areas.

Even so, the moon, from the second day of the month, is the brightest object in the sky (except for the sun of course). Even then it casts a faint shadow (must be a dark place to see a pale shadow), as the moon waxes it becomes more noticeable, easier to pay attention to its shade. As an exercise, try to stand in dark places on different days of a month and see if you recognize the moon shadow yourself. The moon can be seen in daylight. Note the moon in the daytime and the same moon at night. The bright moon of the night seems so pale in the day and hardly more prominent than the surrounding clouds. The brightness of the moon did not change at all but the brightness of the day sky makes it look paler. An additional factor is that the brightness of the moon relates to its entire area in the skies, while usually for stars and planets the brightness is measured for a little dot. This explanation would clarify why Venus in the photo below looks much brighter than the Moon, despite the fact that the moon's brightness is higher.

The moon and Venus. Venus looks brighter than the moon although the moon's brightness is higher

Measuring the speed of light

2012-02-03T09:06:00.000+02:00

How should one measure the speed of light with chocolate? This is a great experiment for kids. One way is to measure how long it takes, from opening a packet to the moment the kids finish it. This is indeed very high speed but still less than the speed of light. The speed of light is one of the most important constants of nature science in general and astronomy in particular but measuring it was a challenge which required complicated experiments.

Today you can conduct an experiment and obtain a very accurate value for the speed of light using nothing but a domestic microwave oven and chocolate bars. The experiment is suitable for children of all ages. First we will describe the experiment and then explain the physics behind it.
Required equipment:
Microwave oven – Almost any microwave will be suitable. Microwaves in which the revolving plate cannot be removed or have more than one radiation source, do not qualify. You must check the frequency of the oven. The frequency usually appears on a sticker at the back of the oven. Most ovens work at a frequency of 2450MHz but it is worth checking anyway.
Note frequency (2450)

Note the frequency 2450Mhz

To perform the experiment you must be able to remove the revolving plate from the microwave and place the chocolate bar on a plate in parallel to the door as sjhown in the following picture:

The chocolate lying in the microwave

Start the microwave at maximum power for half a minute to let some of the chocolate melt, remove carefully and put on a flat surface.
Please note that there are places that the melting is observable (three places) and other places did not melt at all. Find the distance between two places which have not melted at all. From the photo, the distance is about 6cm (2.362 inches)

Measure between two non-melted places in the chocolate

All that's left to do is simple arithmetic:
(Distance * 2 * frequency) divided by (100,000) KM/Sec which is to be used if the distance is measured in centimeters
Or
(Distance * 2 * frequency) divided by (77,335) Miles/Sec which is used for distance in inches

In our example (sorry U.S. guys, the metric system rules!):
(6*2*2450,000,000)/100,000 = 294,000 KM/second (~182000 Miles/Sec). Amazing.
Why does it work?
Electromagnetic waves are moving at the speed of light (almost, it is little less due to the air, but it really does not matter for the experiment). Microwave structure causes the wave to be a standing wave.

Standing wave - Source: Wikipedia

Notice the red dots on the wave, which always remain at the same height. Where there is no movement there is no heat and energy. Also, there are the peaks of the wave, at which the warming will be greatest. For this reason there are rotating plates in the microwave so the food will be evenly heated.
The photo shows that the distance between two points with zero energy is exactly equal to half of the wavelength. These are the places where the chocolate has not melted at all. The Wave formula says that the wave length * number of waves (frequency) = wave speed.
So we get the frequency from the microwave manufacturer, the wavelength, we measured with the chocolate. All we need is to put them into the formula (division is to transfer from centimeters to kilometers) and get an amazing precise result for the speed of light.

A rockect and a sundog

2012-02-03T09:01:00.002+02:00

Sometimes, unexpected things happens. During a quite ordinary Launch of the Solar Dynamic Observatory (SDO), an important mission to research the Sun, the rocket passed near a sundog when it reached a supersonic speed and broke it apart. Notice the shock-wave created by the rocket. The video was taken by 13 years old Anna Herbst.

Sun dogs are an atmospheric phenomenon which due to ice crystals in the clouds creates a bright image on both sides of the Sun (Hence the terms dog). It is not often visible from Israel since it is regularly not cold enough here, but If you observe carefully you will see them from time to time.

SDO has a close encounter with a sundog. Movie formats: 10 MB Quicktime, 1 MB mpeg-4. Credit: Anna Herbst of Bishop, California.

Another video showing the entire launch and the shock-wave:

The Space Shuttle

2012-02-02T10:25:00.000+02:00

The space shuttles were designed as a continuation of the American space program after the Apollo program ended officially in 1975. Unlike the Apollo spaceships which were designed for a single use (most of the Apollo spacecrafts remained in space or burned in the atmosphere. The remaining capsules were distributed to several museums), the shuttles were designed to be launched as a rocket and to land just like an airplane. The first space shuttle took off in 1981. Its commander was John Young. His name is unknown to many, but he is a veteran astronaut and has a very long career at NASA. John Young was an astronaut in Gemini, two Apollo flights, one of them (Apollo 16) he commanded and landed on the moon, and was a natural choice for the first pilot of the new spacecraft. The shuttle Columbia first flight was a success.

The first flights were mainly for research purposes or for placing satellites in orbit. With the beginning of the construction of the International Space Station, most tasks were to build the station. The shuttles brought parts to the stations and the astronauts connected them to the station in space walks (known as EVA – External Vehicle Activity). With the development of the space station, more and more tasks are performed by external robots.

The first shuttle disaster was in 1986, when just seconds after the launch of the Challenger (live broadcast of course) the shuttle exploded in the air. I remember myself as a child watching the launch live and the shock that then struck everyone. After the disaster the shuttle was grounded for a few years while the investigation committee wrote long and detailed reports. A member of the investigation team was Richard Feynman, whose personal report was published as an appendix to the official reports and regarded as a masterpiece worth reading in its own right. The report revealed many flaws in NASA activities and the shuttle program resumed only after a long time.

The shuttles achieved many successes, but another disaster, the Columbia disaster which killed Ilan Ramon, was the sign of the beginning of the end. Colombia was launched successfully, but the launch video images already pointed out that there was a problem in the isolation of the shuttle. Investigation reports have shown after the disaster that there were failures in transferring the information, the decision making process of executives and complacency of "to me, it will not happen". During the return to Earth, the shuttle insulation was defect and heat generated due to large atmospheric friction dissolved the Columbia, causing an explosion. The excitement in the country during the launching mission was hard to forget, many of us saw the live launch, and the entire State of Israel was in grieve mourning.

STS-107 Crew

Seated in front are astronauts Rick D. Husband (left); Kalpana Chawla and William C. McCool. Standing are (from the left) astronauts David M. Brown, Laurel B. Clark, Michael P. Anderson, and Ilan Ramon

After grounding the shuttle program yet again, it was decided to take all shuttles out of service by 2010. After the Challenger disaster, a new shuttle was built (Endeavor), but no new shuttle was built after the Columbia disaster, and the three remaining shuttles' (Discovery, Atlantis and Endeavour) schedules changed and many missions were canceled. Today, as only 5 shuttle missions are left, the shuttles are offered for sale for a modest sum of $ 29 million (excluding transfer costs)

Another high-profile mission of the shuttle was STS-125 service mission to the Hubble Space telescope. Many modules of the telescope were outdated, and parts had to be replaced in order for the telescope to function. The mission was approved under pressure from the public, because the importance of Hubble to science and to the entire human culture in general. There has not been another telescope which has enriched our world so much. Despite the risk and cost, the mission was approved and was extremely successful mission. Hubble space telescope will now serve us at least until 2015.

The shuttles always take off from Florida from one of two launching pads (now only one is active, the other has been transformed to use for the next generation of space vehicles). The shuttle is built and integrated in a huge structure. The building is the tallest one story building in the world with the world's tallest doors. The shuttles are transported from that building to the launch pad on a special vehicle at the amazing speed of, hold tight, half a mile per hour. The shuttle is connected to a huge external fuel tank and two booster accelerators. Both the shuttle’s engines and the boosters are active during the launch to create tremendous thrust, and two and a half minutes later the boosters are cut off and fall back to the Atlantic. The shuttle continues on its engines for another eight minutes and the external fuel tank then disconnects and falls to the Indian Ocean.
After that the space shuttle carries out the tasks or connects to the space station. To land, the shuttle just slows down and begins to fall to earth (slowing of 200 mph is enough). Once this process begins it cannot be stopped. The beginning of the reentrance is determined by the exact landing location. The most desirable location is back in Florida, but this depends on the weather in California. Shuttles landing in California make their way back to Florida on a special Boeing 747 at a cost of another million dollars. Around the world there are more airports where a shuttle can theoretically land, in case there is failure requiring emergency landing immediately after launch. In practice, a landing has never taken place outside the United States.

ISS passing by Lrya

2012-02-02T10:20:00.002+02:00

During the evening there was a great ISS pass. Although the skies were very cloudy I manage to observe the pass, together with 5 great children (To whom I give basic astronomy course).

The ISS moved in the Summer triangle, which in this season is already starts to set during the evenning.

Attached are two photos of the ISS and Lyra constellation. I've added some line to give the familiar shape of Lyra. You will probably need to enlarge the photo to see Lyra stars, but bright Vega is clearly visible. The ISS is the long scratch at the left side.

ISS and Lyra constellation

ISS and Lyra constellation with lines

Mars - The red planet

2012-02-02T10:12:00.002+02:00

The best visible planet in these nights is Mars. Mars is the fourth rock from the sun so it is indeed one of our closest neighbors in space. These nights, while Jupiter is setting early and Saturn rising late, Mars dominates the skies the entire night long. Coincidently or not, Mars is currently the nearest to the earth that it will be until 2012.
When Mars is so close (Less than 100 Million km) it is very easy to observe. Even for the naked eye it looks very bright and very red.
Mars is currently in Cancer, but since Cancer is so dim and cannot be seen from within cities, you will find it between Gemini and Leo, around 20:00pm in the Northeast.
Using a telescope at this distance, one can observe details on Mars. Its ice pole (not water ice but CO2 ice) is visible even with small telescopes.
Look at the photo below for the differentiation of Mars size:

By Richard Bozman

Larger scopes will show even more details.
Currently Mars is moving in a retrograde motion. It runs from east to west, which is the opposite direction of the normal motion – towards the east. Mars is getting closest to Pollux (one of the bright stars in Gemini) and the distance which is currently around 20 degrees will be decreased to 5 degrees. Observe Mars every two days or so and the motion will be clearly visible.

Mars has a lot of active electronic equipment on its surface. There are two rovers: Spirit and Opportunity. The rovers were planned for 3 months missions but are living for well over 5 years although facing many problems such as stuck wheels and motors, dust storms, long winters etc.
The Phoenix probe landed last year, and had a successful mission, finding that water ice exists on Mars. The probe is at very north latitude and is not expected to survive the long mar winter (With temperature around -110C). However, scientists at NASA try to listen for any signals form it in case it did manage to survive.
Around mars there are other orbiters, which take fascinating pictures and used for communications from Earth to all things on Mars.

Martian Landscape from NASA

Mars is an attractive location for human settlements. It has an atmosphere with CO2 which theoretically with a little photosynthesis can be turned into a rich Oxygen atmosphere. Deep in Mars there are lots of geothermic energy source, and scientists still looking for evidence of Bacteria or other living things.
Get out and enjoy watching our red neighbor.

How to see the ISS

2012-02-02T09:59:00.000+02:00

It is easy to view and see the International Space Station (ISS), you only need to know where to look and what to look for. The near space around us is constantly active. Dozens of satellites circle the earth in different orbits. Many satellites can be viewed from Earth shortly after sunset or sunrise. Satellites do not shine their own light, but can be seen as they reflect the bright sun light.

Despite the difference between a satellite and an airplane, it is possible to confuse between the two. Eye equipped, satellite seen as a single point of light which is not flashing, in a single color and moving quickly in the sky. Aircrafts, on the contrary, are usually seen as several colored lights, flashing and moving much slower. In addition, the apparent brightness of a satellite varies relatively in fast pace during the transition, and the airplane brightness varies much slowly. The satellite disappears when it enters the Earth's shadow and does not receive more sunlight (or appears when it comes out from Earth’s shadow and starts to receive light from the sun). When the sun is low below the horizon satellites can not be seen (During the summer, satellites can be seen almost the entire night). Several reasons to observe satellites can be found at this link. With little experience, you will be able to point a moving dot in the sky as a satellite.

Large satellites
The satellites which are the most comfortable for watching are the largest: The International Space Station (ISS), space shuttles (STS) and the Hubble Space Telescope (HST). The ISS is orbiting at an altitude of 350 km, with many visible transitions. At its peak, the station can reach brightness magnitude up to -4 (brighter than Jupiter and almost as bright as Venus). Space shuttle travels to the ISS occasionally. When the shuttle and the station had not yet joined, or soon after they parted, the pair can be seen as two successive points of light chasing one after the other on the same path within a few seconds to a minute difference. Repeated observations over two or three days will show how the two dots receding or approaching each other.

During one of the launches of a space shuttle, I noticed that it is already dark here at Israel. Although there were no data for the pass, I went up to the roof immediately after viewing the launch at NASA site and looked toward the approximate place where the shuttle had to appear (by my own calculations). In about 20 minutes after launch, a bright dot of light appeared exactly as expected. Much to my surprise soon after, another bright spot appeared on a similar route but dimmer. After thinking I concluded that the second point was none other than the external fuel tank of the shuttle. After a shuttle launch, its main fuel tank separate after about ten minutes, losing speed and altitude and finally falls into the Indian ocean waters. Since the phenomenon which I watched is quite rare (Because It can be seen only for about 20 minutes and at most of them from unpopulated areas), I found no other amateurs who viewed it. But I found confirmation that it exists in the following picture. Due to the low number of remaining shuttle missions the chance to see this behavior again is little (at least until the next generation of shuttles will be operational).

Even the Hubble Space Telescope can be seen with the naked eye. The HST cruise in higher orbit than the ISS (600 km) and is much smaller. Therefore, its visible magnitude is only about 1.5 at most. Space shuttle mission STS-125 in October 2008 was to upgrade and repair the telescope, giving him at least 5 more years to serve and sends more amazing pictures and data.

Iridium Flares
Another type of observation is on Iridium satellites. The Seattleites are in polar orbits (moving around the earth at an angle of 90 degrees to the equator), passing over the poles. The Iridium satellites are used for communication purpose from anywhere on Earth. Not all of them are operational but all still orbits the earth (except one which crashed in space with Russian satellite). The satellite brightness normally is barley seen with a naked eye but they have relatively large radio antennas which return the sunlight like a mirror to the area along an imaginary strip over the earth. Whoever found within the stripe or a short distance away, will see a flash in the skies for a few seconds. The closer to the center of the strip, the flash intensity is higher and take longer. Iridium flares can be seen almost every day. Particularly bright flashes can be seen even in daylight if the location of the flare in the sky is far enough from the sun (angular distance). This is the time to note that caution is required in observations that occur while the sun is in the sky, as it might cause irreversible damage to eye of the observer without protective measures.

Communications Satellites
Communications satellites are Geostationary. They circle the earth around the equator and remain at the same point in the sky all the time (Their speed is identical to the earth own rotation speed and their height is about 36,000 km). Such satellites are difficult to see and they will appear as a dim star. Their movement speed is very slow, in fact, they will move in the direction opposite the movement of the sky. If photographed without star tracking they will be sees as a single point (compared to stars which will produce arcs). If tracking is used they will appear as an arc while the starts are fixed as dots.

How to photo satellites
Photographing satellites is relatively easy. It requires aiming the camera at the corresponding area in the sky (using a wide field lens). It is best to find a nice constellation that the satellite will pass through, or integrate an Iridium flare with a lovely landscape (buildings, landscape, etc.). Use a long exposure of several seconds, or preferably in manual mode. The result is a strip of light passing through the constellation or in the landscape. Iridium satellite flares start as a narrow point, become wider and narrow again as can be seen in the photo.

(Iridium flare in Hercules - the star-SARIN apparently filmed by the author).

When aiming the camera at the area of the satellite leaves or enters Earth's shadow, see how the brightness changed from white to red;

(The Space station in the Virgo constellations. Entrance to the earth shadow is changing the brightness.

For telescopes owners
It is hard to observe satellites with a telescope due to the high speed of the object. Small satellites will look only as a bright dot, but the International Space Station structure can be seen at 60x magnifications and higher. Another interesting option is to watch satellite on as they move across the sun. This course requires use of special solar filter. Do not look at the sun without appropriate equipment or you will damage your eyes. Satellite's passage over the sun take around a second, but at least you know where to aim your well protected scope; similarly, one can see passes on the surface of the moon.

How to find satellites
You can of course watch the sky looking for satellites. When observing from a dark area you will usually see several satellites during the hour’s right after sunset or before sunrise. However, it is better to come prepared and download location information from the Internet before starting the observation.

Here's an example of two recommended sites.

HeavensAbove: Registration is not mandatory, but it helps to keep your data for future use. The use is required to choose is location (by country and city, or exact coordinates). The site is very friendly and easy to use, and provides detailed maps showings where every satellite should pass the sky (including the direction and height of the starting points, peak and end). The site includes information on the movement of planets and comets as well.

CalSky:This site is rich in information. You can perform queries and receive a detailed report that includes watching a lot of events. The reports are little harder to read but it provides much more information such as transitions over the sun or moon.

The Sleepwalkers By Arthur Koestler

2012-02-02T09:53:00.002+02:00

The sleepwalkers by Arthur Koestler deals with the life of Copernicus, Galileo and Kepler and their scientific findings. As the book name implies, these great man where searching in the dark without seeing or knowing what they are after.

My Father In-laws recommended this book to me and I bought a second hand copy at my favorite online book shop: BetterWorld.

I was a little surprised to see that the book was written more than fifty years ago! But my in-laws told me that Kepler's life has not changed much in fifty years. Fair enough.

The book tells the story of cosmology from ancient times to Newton. Description of ancient theories developed concentrating on how the ancients almost reached the correct theory and discusses at length what had happened to the theory and why it was abandoned in favor of the geocentric concept. Of course, all these theories were based on thought alone. The first theory was based on Ptolemy, a theory that allowed predictions therefore became popular even though it was very complicated to use.

The book shatters many myths.Copernicus revolution was not really a revolution. Copernicus was not renewed almost nothing, and his famous "On the Revolutions of the heavenly orbs" De Revolutionibus Orbium Coelestium is too complicated to read and mainly contains allegations without proof and without a set of rules. A few years ago out of a book "book nobody read" Which is named after a sub chapter in our book.

The use of the Copernican system is even more complicated than those of Ptolemy. With all the changes Copernicus did he would not touch the last sacred cow of the ancient cosmology which is that the paths of the planets are perfect circles.

Perhaps Hebrew translation is justified because most of the book deals with Johannes Kepler who was the first to establish a scientific method, he found physical rules and formulas that allowed to predict the location of each planet in the sky (other simply ignored errors in their predictions). The author shows great sympathy for Kepler, which is the true hero in the affair, Kepler was a decent, loving science, and did not hesitate to retract his initial theory which tracks the movement of planets version is in accordance with perfect three-dimensional bodies. Kepler was open self-criticism, who collaborated with other scientists (although they did not pay him back and did not share their data with him) and his purpose was to reach the truth although the personal price of giving up glory and fame. From this perspective the book is doing a historical justice with Kepler. The book is full of quotations from letters and writings of Kepler which show his criticism of himself and how he admits he made mistakes. Modesty is not characteristic of other scientists at the time, even tough they knew they were wrong, but stood proudly behind their mistakes of other arguments against the request.

Just Such was Galileo. Galileo did not say the sentence "And yet it still move" Eppur si Muove but it was written on his tombstone. His trial court was quite staged, when he denies all the allegations against him and both he and the judges know he was lying, he was not tortured and didn't sat in jail even one day. Galileo was not fair because he completely ignored Kepler's laws which were based and insisted on the incorrect teachings of Copernicus. Moreover, Galileo made his reputation by telescope observations in his book "Starry Messenger" Sidereus Nuncius. Even his own the data were ignored and observations prove and show him that the teachings of Copernicus is wrong. Soon as Galileo insisted and insisted he wrote his book "Dialogues" with false evidence that was completely Otadtianio - "only fools can not see the truth identified. the church could not ignore his actions (although it is very probably that they want to ignore).

The book ends with a very brief discussion bout Newton and the unification of the theories he did. Kepler gave a set of rules for the movements of the objects in the sky while Galileo gave a system of dynamic traffic laws for objects on the ground (the subject is mentioned briefly and without detail in the book). Newton joined the two, how exactly did Newton? It's a matter of other books.

The book appears at the end of a long epilogue that is a manifest philosophy of science. Inside the book appears many citations with historical details about the families of Copernicus and Kepler, including full details of how Kepler chose his second wife out of 11 candidates. The book contains dozens of quotations footnotes, some of the most interesting (The full preface by
Osinaider to Copernicus book and the full sentence in Galileo).

Explore the Galaxy in Glorious 3D from your PC

How to see Venus in daylight

2012-01-28T22:56:00.001+02:00

Venus is so bright that it is visible in full daylight, and looks as a white bright day on the blue sky. It is more easy to see Venus when it is far from the Sun, and less affected by its glare. Follow these instructions to see Venus in the day. First of all make sure that the sun is blocked by a building or a tree. The Sun light is very strong and it will make the task of finding Venus much harder.

Try to see Venus immediately at sunset. This should be quite easy. Remember the spot that you are stand in and make references to other visible items such as buildings or trees. Stand in the same position a day after but 20 minutes before sunset and try to locate Venus a little up and to the east from where it was a day before. Do so for several days, each time a little earlier.
Use the moon to locate Venus. At least once a month the moon is close to Venus. Find the moon first. The moon is much larger than Venus. and is it easier (Although may require time as well) to find it. After finding the moon try to locate Venus. Use maps or internet sites (such as heavens-above) to find out where Venus is relative to the moon.
Use binoculars to locate Venus. Safety first, make sure that the sun is completely blocked and that you can not accidentally look directly at it through the binculars! Although Venus is bright, It will not appear through binoculars if they are not focused properly. In order to use binoculars, focus it beforehand (In the evening before) on Venus and make sure that the focus does not change. Now the binoculars are focused and you can use them to see Venus in the day. After you find Venus through the binoculars, try to see it without them

Here is a photo of Venus and the moon. It was taken on Jan 26th 2012 when the new moon was close to Venus. The new moon is at the top right and Venus is at the bottom left (Press on photo to view full size)

Venus and the moon in daytime

An older photo, Venus is so bright it is seen through the thin clouds.

Venus in daylight

Sun reflection makes building look like it is on fire

2012-01-17T17:43:00.000+02:00

From far away it seems that the building is on fire!

Building on fire?

But there is no need to worry. This is only the sun's reflection which in a specific angle creates this illusion. The sun was very low in the sky, barely minutes before sunset, which explains the dominate red and orange colors. The building is about 7.5km from the camera and covered with glass and this is how it looks. The appearance of the building changed every minute, as the sun moved in the sky, but the best reflection was from the moment that the sun was exactly opposite the building.
Zooming out, the building still seems on fire.

Is it burning?

But zooming further our it is now clear that it is only a reflection

Reflection of the sun

And this is how it looked

Sun's Reflection

Lightning Photography

2012-01-16T15:12:00.000+02:00

How to photograph lightning?

What an astronomer do during the winter? Photographing lightnings of course. Lightning's photography was once a difficult task which is much eased these days due to digital photography. In order to photograph lightnings, You have to put the camera in a protected area from the rain and aim it into they sky where the lightnings are. Of course a lightning exact position is known only after the lightning occurred, so it is recommended to use a wide lens (as wide as possible) which will cover a larger area of the sky. The area covered by the camera shall include the minimum artificial light. Most digital camera are suitable for lightning photography. Mount the camera on a steady tripod, set the camera for long exposures, 10-30 seconds, and hope that a lightning will happen during that period and area of the sky. Make sure that the aperture and ISO values of the camera are adjusted so the photo will not be too white from any artificial light such as cars streetlamps or even the sky-glow.

If your camera supports this feature, you can use the BULB setup in which the camera shutter is closed only when you release it. To use this option you must use a release cable or remote control since you do not want to touch the camera and vibrate it while it is shooting the photo.
Using such a cable will give you the option to sit indoors in the warmth of your house while the camera is working outside for you. Just make sure that the camera is protected from rain and put a protection filter on the lens as well.
Before the digital photography era, you could use the same technique (many long exposure) or buy a specail light detector which triggered the camera when it detects sudden light. It was harder, inconvenient and with greater cost.

Another option is to take a video movie for a long time. After that, you can edit the video, cut the parts that has no lightnings, and even extract single frames from the video. When doing so you can see how the lightning evolve, frame after frame. We recommend to try both methods simultaneously with two cameras! Good lightning storms are not very common and may occur once or twice a year.

Also be ready for many disappointments. You will see many lightning but by the time you setup the equipment it will stop, or get far away making just light patches in the sky without details. Your timing may be incorrect. the camera might catch only the end of the lightning, etc. Nevertheless once in a while a terrific photo will come out! share it with us.

Orange Moon Rising

2012-01-13T11:04:00.000+02:00

Looking at the rising moon is a great experience! The rising moon has a different appearance than a regular "high in the sky" moon. There are two noticeable differences:

The moon looks much larger, even as 2-3 times as it seems later at night.
The moon color is not white, but orange or even red.

Orange moon about 12 minutes after it rises.

How to observe the rising moon

No special equipment is required besides your eyes. However, in order to see the large and red moon it is best to view it as soon after it rises as possible. There are many places where you can check when the moon rises in your area (it varies for different latitudes) for example use the heavens above site. Also make sure that no buildings or mountains block the view in the required direction. After you find a nice location from which to observe, just wait for the moon to rise and observe its color and size.

Why does the moon look so large?
This is a very old question but even today there is not a full explanation for this. The moon of course in not really larger when it rises, quite the opposite. The moon's distance from the observer is larger when the moon rises than during the night (add the radius of the earth), and the moon is actually about 1.5% smaller! You can test this with your camera. Take a picture of the moon when it rises and when it is high in the sky and count the number of pixels (make sure that the same focal length or zoom is used in both pictures). There will be a slight difference, but even if you don't see the difference you will see that the size is more or less the same and that the large moon illusion is indeed an illusion.

Another known method to measure the moon size is by taking a small coin (a dime usually) and holding it in front of your eye with a straight arm. The coin will completely cover the moon. Try different coins with different sizes. Try it when the moon is low and when the moon is high and you will see that the coin covers the moon at the same distance from your eyes which means, again, that there is no size difference.

The "Large moon illusion" has been known for hundreds of years and even Ptolemy mentions it and tries to provide an explanation. The explanation he gave is partially correct. The moon seems to be large because our brain compares it to other low objects such as trees or mountains. Since we know the moon is much larger than the tree the brain interprets it as being large. However, even looking through a tube at the moon, it will still look large even when there is no other object to compare to. Also the direction of your gaze influences this phenomenon. Try either one of the following: try laying down on your stomach and then raising your head, or try to bend down and look upside-down at the moon and see for yourself what happens.

Why is the orange moon or red moon?
The moon is red because of the earth's atmosphere. It is the same reason why the sun looks red when it rises or sets. The atmosphere scatters most of the moon's light (which is the reflected sunlight) but not the red light which has the longest wavelength. The distance that the moon's light travels through the atmosphere is greater when the moon is low in the sky. When the moon is higher the light is not scattered so much and the moon seems to be white.

Note: The moon will look red and large also when it sets. So make sure to check the moon set hour and location as well if it is more convenient to observe.

The Venus Transit of 2012

2012-01-12T13:38:00.000+02:00

What is the Venus transit?
The Venus transit means that an observer on earth sees Venus pass directly in front of the sun. This requires that Venus be exactly between the Sun and the Earth and also that Venus will be on the same plane as the Sun-Earth plane. While generally all planets are on the same plane, there are small differences which makes the Venus transit very rare.

The next Transit of Venus will be at June 6 2012, and will be visible (at least partially) from most of the world. Venus transit is quite rare and there are only 4 passes in 240 years, usually in pairs of two transits within eight years (The last transit was in 2004). Maybe several of the young readers will be able to see the next transit (2117 in case you wonder), but for most of us it is a remarkable chance to observe this interesting phoneme.

Safety is required. Although the transit is similar to a partial lunar eclipse, there are major differences. Venus apparent size is much smaller than the sun, so Venus blocks only a small portion of the sun. During the transit it will not get any colder or darker and if you do not know that there is a transit you will not be able to notice it at all.

To View the transit you will need special equipment. Never look directly at the sun with your eyes or with an optical device. Do not use old films, dark glasses or even welder glasses. The best method is to use special solar eclipse sunglasses. They are not expensive, buy several for family and friends and use them. You will see a small dark circle on the Sun.

Also check your local astronomy club association. The Venus transit is a major events, so many clubs will open their gates and give the public the chance to view the transit through a telescope. Even if you do have your own telescope and binoculars, don't use them since viewing the Sun requires special equipment.

The movement of the planets

2012-01-08T15:28:00.000+02:00

What are planets? Planets are moving stars. While most of the stars are fixed in the sky rotating as a whole unit and never changes their location relative to each other, the planets are different and may appear in different places in the sky, not the whole sky but rather a thin band which is called the Zodiac. From very ancient times, people notice that there are 7 stars which move, and the Greeks called them planets (which mean wanderers). These ancient 7 "classical planets" were the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. Earth of course was in the middle of the universe, still and not moving, and Uranus and Neptune too faint to see.
Today there is a formal definition of planets, There are exp-planets (Planets orbiting stars other than the sun), and many planets has planets of their own (moons). However, Planet is still moving in the sky and it is very easy to observe this movement with your own eye just like our ancient predecessor thousands of years ago.
To observer the movement of the planets you will need to identify them. It is not hard since planets are quite bright, being easily noticed in the sky (especially Venus and Jupiter), and also because they are not part of any constellations in the zodiac. If you have troubles try using software such as stellarium or applications for you iPhone or Androids mobile devices. In order to see the movement you will have to choose a reference start, a bright star which is close to the planet and you can measure the distance between them.
The planets which are closest to the sun, Mercury and Venus are moving fast. However Mercury is hard to find so leave it alone. Jupiter and Saturn moves slow so it takes at least two weeks between observations to see noticeable change.
The following photos present Jupiter and Mercury near one of their conjunctions. I used Jupiter as a reference star to demonstrate the movement of Mercury. Jupiter is also moving but in a period of 5 days its movement is negligible. Let's start with the photos. Jupiter is always the left dot and mercury is seen much below it.

Jupiter and Mercury day 1

After a day Merucry is still below Jupiter.

Jupiter and Mercury day2

After another day, Merucry and Jupiter are almost at the same height. The photo was taken in twillight so it may be hard to see both planets which appears as pale white dot. Try to enlrage the photo to see better.

Jupiter and Mercury day3

After another day Mercury is higher than Jupiter.

Jupiter and Mercury day4

And after another day, Mercury is much higher than Jupiter.

Jupiter and Mercury day 5

After another day Mercury and Jupiter were too far to take a photo together.