Wednesday, November 28, 2012

Moon Perigee and Apogee

Patience pays off. Six months ago I took a picture of the moon at Perigee, the closest point in its orbit to Earth. It was a full moon. Today (28-Nov-2012) it is a full moon again, but the moon is furthest away from Earth in its orbit - Apogee. The moon is indeed smaller, and in the exact ratio of the distances - about 15%. It is an experiment that I have wanted to do for a very long time and I am happy that I've completed it successfully.
The Apogee moon photo is from the moonrise which gives the orange tint to the picture. The reason for the orange moon is detailed in the following article.

Here is a photo of the two moons. It is not a matter of resizing. The same camera, same setting, same zoom were done to both photos. A picture is worth a thousand words.
Moon comparison at Perigee and Apogee
Moon comparison at Perigee and Apogee

Monday, November 26, 2012

Carnival of space #277

Hi and welcome again to the Venus Transit for another carnival of space. The Transit is history at least for the next hundreds years, but there is plenty of other stuff going around so take a small break and dive into this issue.
Carnival of Space
Carnival of Space


Ray Sanders from "Dear Astronomer" has a new episode of "The Cosmic Ray Show" airing on November 27th at 7:00PM Pacific. Join Ray along with his co-host, astronomer Jerry Hilburn, and special guest, astronomer Dave Reneke as they discuss the recent solar eclipse, and take a virtual tour of the astronomical sights of the southern hemisphere. Featured musical guest is Google+ sensation, Ryan Van Sickle.

Is there a role for airships in the space age? This post from tranquility base introduces two novel ways that airships can contribute to space exploration. 

Centauri Dreams looks at Rod Hyde's ideas on laser fusion, as developed in a starship paper he wrote in the 1970s along with collaborators at Lawrence Livermore National Laboratory.

Two articles from Next Big Future:
In an interview with NPR, John Grotzinger, the principal investigator for the Mars Curiosity rover mission, indicated that the data [that they are getting from Mars Science Laboratory Sample Analysis at Mars Instruments] is gonna be one for the history books. It's looking really good. The announcement will be in a few weeks after more tests and confirmations are run. Curiosity can not directly detect the presence of Mars life. Curiosity can detect organics, which would be the presence of the building blocks of life on the surface of Mars. 

Information acquired by L2 this week revealed plans for a “game-changing” announcement as early as December that a new commercial space company intends to send commercial astronauts to the moon by 2020. According to the information, the effort is led by a group of high profile individuals from the aerospace industry and backed by some big money and foreign investors. The company intends to use “existing or soon to be existing launch vehicles, spacecraft, upper stages, and technologies” to start their commercial manned lunar campaign. New Space Watch identifies the company Golden Spike as the company that will have the commercial manned mission to the moon. It is registered in Colorado to Alan Stern, a former administrator of NASA's Science Mission Directorate, and now working on the New Horizons Pluto mission at the Southwest Research Institute in Boulder, Colorado.

Universe Today also relates to the new findings on Mars. The Mars Science Laboratory team has hinted that they might have some big news to share soon. But like good scientists, they are waiting until they verify their results before saying anything definitive.
Once again people are worrying that astronomical alignments will cause Eathquakes, Astroblogger analyses why the latest batch is nothing to worry about. If alignments and earthquakes aren't enough, now the largest solar flare recorded (the Carrington Event) is being attributed to a planetary alignment. But it just aint so.

Lucky Astroblogger is an Aussie so he had a great chance to view the last solar eclipse. Lucky for us, he shares his photos with us!

Pamela Hoffman from Everyday Spacer sends two articles: Attend an airshow and Watch a partial Lunar eclipse

And as a last treat watch the latest video from Amy Shira Teitel  author of VintageSpace. I already subscribed to her YouTube channel and eager to see new episodes.




That's all for this issue. Hope you all have long days and clear nights.








Thursday, October 4, 2012

What Voyager is doing now

In our last article about Voyager, we discussed Voyager's last photo from space. After taking that photo which was the end of the grand tour, it seemed reasonable to shut down the mission and let the spaceships continue their eternal journey in space. However, since the spaceships' condition was still very good, most of the systems still functioning and their location was the furthest any object had arrived it seemed sensible to find a new mission for Voyager and not let it waste in space.
Every end is a new beginning and the end of the "Grand Tour" was the beginning of VIM - "Voyager Interstellar Mission". You might have heard on the news that Voyager left or is about to leave the solar system. This is not accurate and we need to first determine where the solar system ends. If our criteria for the edge of the solar system is the distance at which the sun gravity has little effect on celestial bodies, Voyager is still in the inner part of the solar system. The influence of the sun gravity reaches to a distance of about 1 light year from the sun, to the end of the Oort cloud.
A definition which is better for our purpose, is the border of the magnetic field of the sun. The sun's magnetic field moves with the sun. As it is illustrated in the diagram below, the magnetic field seems like a bullet advancing with the sun. It travels with and in front of the sun and stretches to a great distance behind it. Charged particles from the sun (a.k.a "Solar wind") travel very fast, they start to slow down when they meet other charged particles coming from space (a.k.a "Space wind"). The area where Voyager 1 is currently traveling is the place where these two "winds" meet ("wind" is used as a metaphor).

Voyager Interstellar Mission
Voyager Interstellar Mission. NASA
In this diagram, the inner circle is the Solar system with its 8 planets (as we said before, there are other objects further away which orbit the sun). The Heliosphere, the sun's atmosphere, reaches beyond and behind the sun, and the Heliosheath is the area where Voyager 1 is currently traveling.
The size of the Heliosheath is unknown and it is changing constantly. The scientists hope that Voyager will be able to cross it and reach the area of the bow-shock. Voyager's energy supply (we will deal with this matter in our next article) will last for the next 10-15 years. In order to conserve energy, all unnecessary instruments were shutdown long ago, and only 5 systems are still functioning. These systems include the communication system, the magnetometer and other instruments to measure the speed and direction of charged particles.
What Voyager discovered is that particles from the sun's direction become slower and slower, and particles not from the sun's direction become more and more common (and with greater speed). This means that Voyager is getting nearer to the area where the majority of particles will not be from the sun (and only in that sense, leaving the solar system). So, it is now a race against time, to get as far as possible before all Voyager's energy is used. The current distance of Voyager 1 from the sun is 120 AU (astronomical unit - the distance from the sun to earth - 150,000,000 KM) and its speed is 3.6 AU per year. In 10 years it will reach a distance of 150 AU from the sun, and if it will still function we will learn a lot about the strange conditions at that far place. Voyager 1 is the front lab of humanity and it provides sci-fi enthusiastic some food for thought  about spaceship travels to other stars and planets.

See Voyager exact distance from earth and sun

Previous articles
Voyager - The grand tour
Voyager's last photo

Friday, September 14, 2012

Voyager - The Last Photo

Most people like family photos, and the more participants the merrier. But there is one family that it is particularly hard to photograph together, mainly because the distances between the brothers and sisters of this family can be above 5 billion KM and they will never get any closer. An experienced photographer will distance himself as far as possible and try to get just the right angle to include as many members of the family as possible. The family we are discussing is the solar system with the Sun and the planets. When Voyager finished the grand tour, it was in a great position to catch most of the family members in one photo. The spaceships' cameras were not needed anymore, both spaceships were not expected to observe additional celestial objects, and the decision was to take one last photo before shutting the cameras down forever. You remember that there were two Voyager spaceships, and to take that special photo, Voyager 1 was chosen, simply because it had a better viewing point. Voyager 1 left the ecliptic plane and was high above it, providing a better photography angle than Voyager 2 who was still near the ecliptic.
There were some other obstacles. The sun (the old grandmother of the family) is extremely bright. The planets (brothers and sisters) are dim and far apart from each other, and the moons (grandchildren) are just too small and dim, so the family portrait  is not really a single picture but a mosaic of about 60 photos combined together, taken with different exposure times and filter. The last of the Voyager mosaic is shown below, taken on February 14th 1990.
Voyager I portrait of the solar system.
Voyager I portrait of the solar system. Credit: NASA
OK, I am sure you did not exactly expect this as a family portrait but it is the best possible composition. The grey squares are the individual pictures, as mentioned, more than 60 frames were needed to get all members of the family, but as often happens, someone is still missing. The letters designate the planets (J - Jupiter , E - Earth, V - Venus , S - Saturn, U - Uranus, N - Neptune) and the bright dot is the sun.  Mercury and Mars are missing from the portrait. Mercury was too close to the sun, and Mars could not be found. Pluto which in 1990 was closer to the sun than Neptune and still a distinguished member of the solar system (until it was kicked out to be a dwarf planet) was too dim and was not included in this picture, maybe as a prophecy to its destiny 15 years later.
The picture is in a very high resolution so please click on it to enlarge it. You will see excerpts presenting the planets themselves. It is possible to see some details on Jupiter and a hint of Saturn's rings. Uranus and Neptune seem larger but this is because the long exposure time of 15 seconds which gave them a little smudge. The sunlight is visible in many pictures, and the camera hardly managed to capture planet Earth. The size of our little planet is less than one pixel and the photograph that shows it got its iconic name by no other than Carl Sagan: "The pale blue dot"

Pale Blue Dot
The pale blue dot. Credit: NASA

After these photos, the Voyagers' cameras were shut down forever. Cameras need power, and power is a rare resource in a little spaceship, but these photos are part of the heritage that Voyager left us.

Previous Articles in the Voyager's series:
Voyager - The Grand Tour

Monday, September 10, 2012

Carnival of space #266

Hi and welcome to a new issue of "Carnival of space" your weekly gateway to astronomy and space articles and news.



Cheap Astronomy delivers a fine podcast on the Fine Structure Constant, described by Richard Feynman as 'the greatest damn mystery in physics'. 

Nextbigfuture send us 3 articles the first one is dealing with NASA is funding development into aneutronic nuclear fusion for space propulsion.
The second item from Nextbigfuture is about the lunar space elevator kickstarter which has raised over $70000 and still had one week to go. By the weekend it will still have a few days left and should be over $80,000 and the way to passing the $100,000 level. At the $100,000 - back in business for real, have a series of experiements and $250,000 - try for to climb to the limit of balloon technology , about 20 miles / 30 kilometers.
The last from Nextbigfuture is about NASA NIAC phase 1 project Water Walls (WW). Water walls takes an approach to providing a life support system that is biologically and chemically passive, using mechanical systems only for plumbing to pump fluids such as gray water from the source to the point of processing. The core processing technology of Water Walls is FORWARD OSMOSIS (FO). Each cell of the WW system consists of a polyethylene bag or tank with one or more FO membranes to provide the chemical processing of waste. WW provides four principal functions of processing cells in four different types plus the common function of radiation shielding.

As school year is starting in many places around the globe, the post-Labor Day week got us thinking about school and education as it relates to Chandra and X-ray astrophysics.

Weirdwarp has an article about Voyager 1 which has travelled the furthest any -made object has travelled in a straight line (well almost a straight line). We will probably and hopefully overtake it one day with future space technology but today it can bask in glory.
Voyager Model.
Most of Mars interest is focused on Curiosity, but there are other rovers doing great job on our red neighbor. The Meridian Journal tells us about Opportunity rover is examining an interesting rock outcrop which may contain some of the long-sought clay deposits.


Peter Lake takes a look at the newly discovered 375m Asteroid that will pass at about 7.4 lunar distances on the 14th. It is a little unusual these days to find such a big asteroid less than three weeks before its closest approach.


The second episode of The Cosmic Ray Show will air on September 11th, 2012 at 10:00 PM Pacific!
Our special guest for our second episode is Dr. Alan Stern, principal investigator for the New Horizons mission to Pluto. In addition to his scientific duties, Dr. Stern is also a founder of a new start-up, Uwingu. Uwingu aims to help fund space education, exploration and research.



This is all for this week, may your days be long and your nights clear. The next new moon will designate the newly Hebrew year (5773), best regards and happy new year "Shana Tova" to all of you.


Friday, August 31, 2012

Voyager - The Grand Tour

Voyager spaceships deserve their names. They travel in space farther away than any other object and will continue to do so for many more years. Celebrating 35 years for the Voyager launch, we will dedicate several articles which will present various aspects of this great mission, the longest ongoing active mission that NASA holds.
Note: Although there are two Voyager spacecrafts we will mostly use the singular form, unless necessary to differentiate between the two spaceships.

When the Voyager mission was first planned there were so many question marks about the solar system. Our knowledge was just a fraction of the knowledge we have today. Many details about the gas giants, especially Uranus and Neptune were totally unknown and spaceships only traveled to our near neighbors: the moon, Venus and Mars.

The first problem for space traveling is the great distances between the destinations, and the fact that there is a need to get there in a reasonable time, otherwise the spaceship itself might not work properly. Sending something directly to the edge of the solar system was not possible and required extremely large rockets and quantities of fuel. That was until someone (and there is some disagreement about who exactly is that someone, so I will not write any names) thought of a marvelous idea. There was no need to go directly to Neptune. It was enough to reach Jupiter at the correct time and angle. The massive gravity of Jupiter would accelerate the spaceship even more, and throw it outward toward Saturn. It was possible to do the same at Saturn, throwing the spaceship to Uranus and again to reach Neptune, in a reasonable time of about 10 years only (and not 25) which was less than the spaceship's expected life time. The term for such a maneuver is Gravity Assistance or the Slingshot Effect. This conclusion was reached in 1965.
The calculations of the such trajectories are extremely complicated, as the spaceship must be at the right distance from the planet, at the right angle and at  the right speed, otherwise it might crash on it or go into orbit around it. The Voyager itself had an engine and some fuel but this engine was used for minor trajectory corrections (or to give just a bit more of acceleration). The calculations required many computer hours (the computers at that time were much less powerful than today), but eventually such calculations were finished (by hand or with computers) and they showed that all planets would be aligned for such a tour in the late seventies!
However there were many political issues as well. In the early 70', the Apollo program was coming to an end, NASA started to work on the Space Shuttle programs and the planetary science was neglected a little. However, JPL started to present the idea of the "Grand Tour" to the end of the solar system, not just to near planets, with much better equipment than the Pioneer spaceships. Finally the green light was given.
Since so many details about Jupiter and Saturn were unknown it was impossible to set exact trajectories until more data was gathered, however it was impossible to wait for a spaceship to gather that data as the correct alignment of planets would pass. Therefore, two almost identical Voyager were sent. The first one, Voyager I's goal aim was to go to Jupiter and from there to Saturn only, providing many details which were required for a finer calculation which were used by Voyager II some months later to manage to travel the exact route to Uranus and Neptune.
Due to some technical reasons the first launch was that of Voyager II in August 20th 1977, and Voyager I just two weeks later on September 5th. Voyager I's speed was slightly higher and it quickly passed Voyager II, thus starting the longest journey ever.


Voyager
Voyager



Tuesday, July 24, 2012

Carnival of Space #259

Welcome aboard to another fine issue of Carnival of space, a collection of the best the astronomy community has to offer.
Fasten your belts and we are starting....


"Gaming for real science!" Want to participate? Technology is making it possible for the public to participate in exploration as they never have before. Because Mars exploration is fundamentally a shared human endeavor, we want everyone around the globe to have the most immersive experience possible. Read more on Links Through Space"

Long-time readers of Dear Astronomer know that I am a pretty hard-core dark sky advocate. As a fan of science fiction and dark skies, I couldn’t resist passing along this video from 2001. From what I’ve heard the footage was archived VHS footage that was recently digitized by Scott Kardel (International Dark Sky Association).

Nextbigfuture - a novel architecture is proposed that would allow for an unmanned interstellar rendezvous and return mission. The approach utilized for the Vacuum to Antimatter-Rocket Interstellar Explorer System (VARIES) would lead to system components and mission approaches that could be utilized for autonomous operation of other deep-space probes. Engineering solutions for such a mission will have a significant impact on future exploration and sample return missions for the outer planets. This paper introduces the general concept, with a mostly qualitative analysis. However, a full research program is introduced, and as this program progresses, more quantitative papers will be released.

Simostronomy - His introduction to the night sky occurred at age five when his mother introduced him to the Pleiades on a crisp, clear, winter night. A book from a kindly librarian brought the rest of the universe into focus and Leslie's quest for knowledge of the night sky took off. As a teen Leslie earned $18 for a mail order telescope by picking 900 quarts of strawberries on his father's farm, earning two cents per quart. The 2-inch refractor arrived a few weeks later and 64 continuous years of night time observing began.

Simostronomy - If you are a visual observer, the eyepieces in your arsenal are as important as the optical tube or mount. One of my goals has always been to find the perfect combination of the fewest number of eyepieces to be able to handle all my typical observing requirements. I don't like to spend time changing eyepieces and refocusing. I want to observe, not focus and fiddle around. My search for the perfect combination of eyepieces for variable star observing has had episodes of experimentation and expense followed by long periods of satisfaction and observing action.

A Cheap Astronomy podcast talks through the OBAFGKM classification of stars and finds there's more to it than just getting fine girls to kiss you.

Land Ho! Riding with robots, using NASA's "Eyes on the Solar Sytem" site to see what the spacecraft carrying Mars Curiosity sees as it approaches the Red Planet over the next few days.

Supernova Condensate - The Frost Line in circumstellar disks marks the point where volatile molecules start to condense into ices. But is it the only such line? Perhaps, as some astronomers have proposed, there might also be a Soot Line to consider...

Astroblog - Views of the Aurora Australis form the recent solar storm of 15 July

The Meridian Journal - The Spitzer space telescope has found a possible exoplanet which is smaller than Earth and may be covered in lava.

Astronomers at the dotAstronomy conference made good use of their video cameras to make two films: "Science: it's Universal" & "Sh*t Astronomer's Say"

Sunday, July 15, 2012

Jupiter occultation summary

Jupiter occultation stood up to my expectations. I didn't set up anything in advance due to the weather, I just got all the equipment ready and outside the house. I set up the alarm clock for 3am and tried to get in a few ours of sleep. When the alarm went off, I went out to see the moon which just rose in the north-east. Even with the naked eye the view was fascinating, and Jupiter was very near to the edge of the moon. I set up everything and then Venus rose as well. Venus showed a lovely crescent phase! Then all there was to do was to take pictures and wait. The weather was clear but humidity was very high. I used two telescopes: one for viewing (a small refractor with x100 magnification) and another one for photos and video (Bresser N130 with Philips SPC 900 Webcam).
The following pictures show the first part the disappearance. It happened so quickly that you can easily miss it. I just pressed the button to take the video and moved to the other telescope for visual observation. It took around 80 seconds and it seemed just like the moon swallowed Jupiter.
Jupiter occultation
Jupiter occultation
And the video (I was some seconds too late to start it, sorry)



But don't worry, it came back after an hour, you might even see the famous earth shine
Jupiter occultation
And as dawn arrived I took a photo of the general view of the sky with the moon, Jupiter and Venus just before sunrise. I followed Jupiter to see how long after sunrise I could see it with the naked eye. Since it was so close to the moon it was relatively easy to see it even 25 minutes AFTER sunrise.
The moon Jupiter and Venus
The moon Jupiter and Venus (bottom) after the occultation
And another bonus was that at 5:40am I saw the live launch of Soyuz for the ISS over the internet.


Thursday, July 5, 2012

Jupiter Occultation

An occultation is an event in which a celestial body covers another, farther away object.  Usually, the term is used to describe an event when the moon covers a star or a planet or when a planet or an asteroid covers a far away star. On July 15th there will be a marvelous Jupiter occultation. The moon will cover Jupiter for about an hour (the exact time and durtaion of the occultation is  dependent on the observer's location).

Occultations can also contribute to science. During the 80s Uranos occulated a distant star. Photos of the events showed that just before and after the occultation the star blinked several times. The theory was that Uranus has a set of rings (like Saturn). When Voyager 2 reached Uranus it detected and photographed the predicted rings.

Seeing Jupiter's occultation is possible with the naked eye, but the look through a telescope, even using a small magnification, is marvelous. At first, two of Jupiter's large moons (Io and Europa) will disappear behind the moon, then Jupiter will disappear and then the other two moons (Ganymede and Callisto). It is best to check your local almanch for the exact times. The times given here are appropriate for Israel. Unfortunately the event will not be seen in the United States at all, but US observers will have a Venus occultation in August!

Here are some tips for occultation observations:

  1. Start early - Even the view of Jupiter so close to the moon is great so start watching it as soon as possible (Which will be when the moon and Jupiter rise in the morning)
  2. Check the weather - If weather is bad its worthwhile to drive off to somewhere else. Check with other astronomers in different cities nearby
  3. The occultation itself is very very short - a few seconds only, so make sure you know exactly when it happens.
  4. If you have two telescope use both. If you want to try and photograph as well you might need help. It is difficult to handle both at the same time and you might need to choose between visual observation or astrophotography
  5. Check out when the end of the occultation occurs. You will need to be very accurate for this, and you can divide your attention between visual and photography to the start and end of the occultation
  6. Do not forget the moons! Watch carefully until all moons are occulted.



Jupiter occultation times for Israel (GMT+3)
Date: July 15th (The night between Saturday and Sunday)
Occultation start: 4:03
Occultation end: 5:06
Jupiter Occultation - Illustration
Jupiter Occultation - Illustration


Wednesday, June 6, 2012

Venus Transit Summary

Nothing but a very big WOW. The Venus transit in Israel was visible on June 6th from sunrise to external egress, a little more than 2 hours. I had to wait until all my US friends saw it and went to sleep. I was very worried about clouds and hardly slept at night. At 5am the skies were cloudy but not very, so I was confident that even if I miss sunrise (because of the clouds) they would disperse later on and it would be OK. I started the observation with the almost full moon in the west.

almost full moon
Almost Full Moon
After that I climbed to the roof of a tall building and saw that the entire east was covered with clouds... Not so good...

Cloudy east
Cloudy East
But two minutes later, an area in the sky became brighter, that was the sun, so I aimed my camera quickly and grabbed this photo. At this point, I couldn't see anything with my eyes or use a filter, but the moment that I saw on the camera screen that there was a big black dot on the sun I was extremely happy. A complete round sun with a dot is nice but a very ordinary photo. The following photo is anything but ordinary. The rising sun in a deep purple color, the clouds below and above the sun, the buildings in front and the buildings through the sun, and of course, Venus - a composition that will not be repeated for another 105 years!

Venus transit at sunrise
Venus transit at sunrise

Here is a close-up of the Sun, the buildings are seen clearly, and it looks like sci-fi...
Venus transit at sunrise
Venus transit at sunrise
A few minutes afterwards and the disc of the sun passed through the first layer of clouds. This photo is still without a filter and it shows Venus, distorted by the heavy Earth atmosphere (the sun is still very low in the sky), and another surprise - one of the several sunspots! The photos of the rising sun were great but I still had to set up my observation.
Venus transit at sunrise
Venus transit at sunrise
For me, astronomy is not just a hobby but a passion I like to share with others. I set up a public observation in my town, and after seeing the sunrise I quickly went to the place where I planned the observation and setup the telescope. People started to come at around 6am. They looked at the sun through the telescope and through the eclipse's sunglasses, received information and explanations about what they saw and took photos through the telescope or through my filters.

Venus transit observation at Givat Shmuel Israel
Venus transit observation at Givat Shmuel Israel
 After that I photographed ordinary photos of the whole sun through a solar filter. Many sunspots are visible as well.
Venus Transit
Venus Transit

The event slowly came to an end. The next photo shows the internal egress, when Venus touches the limb of the sun from the inside. For another 20 minutes or so Venus exited the sun completely becoming a morning star.
Venus transit internal egress
Venus transit internal egress
The observation took about 2 hours, and about 100 people, young and old, male and female took part in it. It was great fun and a rare experience and I am very happy I took a part in it.

To finish, here is a short video of the sun rising.


Venus Transit Timetable

Here is the timetable for the 2012 Venus transit.

 Read more about Venus Transit at the Venus transit FAQ page

Venus Transit 2012
Venus Transit 2012 - Nasa

There are five timing points for the event:
External Ingress - Venus first touches the limb of the sun. The transit begins - 22:09:38 UT
Internal Ingress - The first moment that all of Venus is in front of the sun - the full transit begins - 22:27:34 UT
Greatest Transit - The exact middle of the transit. Venus is at its smallest distance from the sun center - 01:29:36 UT
Internal Egress -  the last moment that all of Venus is in front of the sun - 04:31:39 UT
External Egress - the last moment that Venus partially blocks the sun. The transits ends (for the next 105 years!) - 04:49:35 UT

You can use this application to locate your exact time (Taken from the following superb site which also deals with Venus transit)




Transit times



You can also use the following Time table (from NASA). The times are give in UT (Universal Time), you will need to add or subtract hours from UT according to your timezone and your daylight savings time (most northern countries will have daylight time in June, southern countries will not).



US Major cities timetable for Venus Transit:(Times are in UT)
You will see that the US will have the transit on the 5th of June 2012, and will be able
to see only the beginning of it (except Hawaii)

Read more about Venus Transit at the Venus transit FAQ page


                   ------------------- T r a n s i t   C o n t a c t s -------------------

Location Name       External Sun   Internal Sun   Greatest Sun   Internal Sun   External Sun
                    Ingress  Alt   Ingress  Alt   Transit  Alt    Egress  Alt    Egress  Alt 
                     h  m  s  °     h  m  s  °     h  m  s  °     h  m  s  °     h  m  s ° 

Akron               22:03:56  30   22:21:35  26      --      -      --      -      --      - 
Albany              22:03:36  24   22:21:15  21      --      -      --      -      --      - 
Allentown           22:03:42  25   22:21:21  22      --      -      --      -      --      - 
Atlanta             22:04:17  31   22:21:56  27      --      -      --      -      --      - 
Austin              22:05:10  42   22:22:48  38   01:25:31   0      --      -      --      - 
Baltimore           22:03:46  26   22:21:26  22      --      -      --      -      --      - 
Baton Rouge         22:04:46  36   22:22:25  32      --      -      --      -      --      - 
Birmingham          22:04:24  33   22:22:04  29      --      -      --      -      --      - 
Boise               22:05:40  54   22:23:15  51   01:25:39  19      --      -      --      - 
Boston              22:03:31  22   22:21:10  19      --      -      --      -      --      - 
Buffalo             22:03:48  28   22:21:26  25      --      -      --      -      --      - 
Charleston          22:04:00  29   22:21:39  26      --      -      --      -      --      - 
Chicago             22:04:12  34   22:21:49  31      --      -      --      -      --      - 
Cincinnati          22:04:07  32   22:21:45  28      --      -      --      -      --      - 
Cleveland           22:03:56  30   22:21:35  26      --      -      --      -      --      - 
Columbia            22:04:06  28   22:21:46  25      --      -      --      -      --      - 
Columbus            22:04:02  31   22:21:40  27      --      -      --      -      --      - 
Dallas              22:05:00  41   22:22:38  37   01:25:34   0      --      -      --      - 
Dayton              22:04:05  31   22:21:44  28      --      -      --      -      --      - 
Denver              22:05:11  47   22:22:47  44   01:25:36   9      --      -      --      - 
Des Moines          22:04:30  39   22:22:07  35   01:25:49   2      --      -      --      - 
Detroit             22:03:59  31   22:21:37  28      --      -      --      -      --      - 
El Paso             22:05:38  49   22:23:16  45   01:25:24   8      --      -      --      - 
Flint               22:04:00  31   22:21:37  28      --      -      --      -      --      - 
Grand Rapids        22:04:05  33   22:21:43  30      --      -      --      -      --      - 
Harrisburg          22:03:46  26   22:21:25  23      --      -      --      -      --      - 
Hartford            22:03:35  23   22:21:14  20      --      -      --      -      --      - 
Honolulu            22:09:59  85   22:27:38  89   01:26:12  49   04:26:30   9   04:44:29   5 
Houston             22:05:03  40   22:22:42  36      --      -      --      -      --      - 
Indianapolis        22:04:11  33   22:21:49  30      --      -      --      -      --      - 
Jackson             22:04:38  35   22:22:17  32      --      -      --      -      --      - 
Jacksonville        22:04:16  28   22:21:57  24      --      -      --      -      --      - 
Kansas City         22:04:37  39   22:22:15  36   01:25:44   2      --      -      --      - 
Lansing             22:04:02  32   22:21:40  29      --      -      --      -      --      - 
Lincoln             22:04:41  41   22:22:17  38   01:25:45   4      --      -      --      - 
Little Rock         22:04:39  37   22:22:18  34      --      -      --      -      --      - 
Los Angeles         22:06:17  58   22:23:53  55   01:25:24  18      --      -      --      - 
Louisville          22:04:12  33   22:21:50  29      --      -      --      -      --      - 
Madison             22:04:15  35   22:21:52  32   01:25:57   0      --      -      --      - 
Memphis             22:04:31  36   22:22:10  32      --      -      --      -      --      - 
Miami               22:04:23  26   22:22:05  22      --      -      --      -      --      - 
Milwaukee           22:04:11  34   22:21:48  31      --      -      --      -      --      - 
Minneapolis         22:04:23  38   22:22:00  35   01:25:56   4      --      -      --      - 
Montgomery          22:04:25  32   22:22:05  29      --      -      --      -      --      - 
Nashville           22:04:19  33   22:21:58  30      --      -      --      -      --      - 
New Haven           22:03:36  23   22:21:15  20      --      -      --      -      --      - 
New Orleans         22:04:44  35   22:22:23  31      --      -      --      -      --      - 
New York            22:03:39  24   22:21:18  21      --      -      --      -      --      - 
Norfolk             22:03:49  25   22:21:29  22      --      -      --      -      --      - 
Oklahoma City       22:04:55  42   22:22:33  38   01:25:36   2      --      -      --      - 
Omaha               22:04:38  40   22:22:14  37   01:25:46   4      --      -      --      - 
Orlando             22:04:20  27   22:22:00  24      --      -      --      -      --      - 
Philadelphia        22:03:42  25   22:21:22  21      --      -      --      -      --      - 
Phoenix             22:05:55  54   22:23:32  50   01:25:24  13      --      -      --      - 
Pittsburgh          22:03:53  28   22:21:32  25      --      -      --      -      --      - 
Portland            22:05:57  57   22:23:31  54   01:25:45  23      --      -      --      - 
Providence          22:03:32  22   22:21:12  19      --      -      --      -      --      - 
Raleigh             22:03:57  27   22:21:36  23      --      -      --      -      --      - 
Richmond            22:03:51  26   22:21:30  23      --      -      --      -      --      - 
Riverside           22:06:14  58   22:23:50  54   01:25:24  17      --      -      --      - 
Rochester           22:03:44  27   22:21:23  24      --      -      --      -      --      - 
Sacramento          22:06:15  60   22:23:50  56   01:25:32  21      --      -      --      - 
St. Paul            22:04:23  38   22:22:00  35   01:25:56   4      --      -      --      - 
St. Louis           22:04:25  36   22:22:02  33      --      -      --      -      --      - 
St. Petersburg      22:04:25  28   22:22:06  25      --      -      --      -      --      - 
Salem               22:06:00  58   22:23:34  55   01:25:44  24      --      -      --      - 
Salt Lake City      22:05:33  52   22:23:08  49   01:25:35  15      --      -      --      - 
San Antonio         22:05:15  42   22:22:54  38   01:25:29   0      --      -      --      - 
San Diego           22:06:18  58   22:23:54  54   01:25:23  16      --      -      --      - 
San Francisco       22:06:21  61   22:23:56  57   01:25:31  22      --      -      --      - 
San Jose            22:06:20  60   22:23:56  57   01:25:30  21      --      -      --      - 
Seattle             22:05:50  56   22:23:24  53   01:25:49  23      --      -      --      - 
Springfield         22:04:21  36   22:21:58  32      --      -      --      -      --      - 
Syracuse            22:03:41  26   22:21:20  23      --      -      --      -      --      - 
Tallahassee         22:04:24  30   22:22:04  27      --      -      --      -      --      - 
Tampa               22:04:24  28   22:22:05  24      --      -      --      -      --      - 
Toledo              22:04:01  31   22:21:39  28      --      -      --      -      --      - 
Topeka              22:04:41  40   22:22:18  37   01:25:43   3      --      -      --      - 
Tulsa               22:04:48  40   22:22:26  37   01:25:39   1      --      -      --      - 
Washington, DC      22:03:48  26   22:21:27  23      --      -      --      -      --      - 


Major International cities Venus transit timetable (NASA)
All times are in UT and must be adjusted to the local time

Read more about Venus Transit at the Venus transit FAQ page
Entire Europe, Middle East and West Asia will see the transit on 6th June 2012. Most sites will only see the final phase of the transit after sunrise.

                    ------------------- T r a n s i t   C o n t a c t s -------------------

Location Name       External Sun   Internal Sun   Greatest Sun   Internal Sun   External Sun
                    Ingress  Alt   Ingress  Alt   Transit  Alt    Egress  Alt    Egress  Alt 
                     h  m  s  °     h  m  s  °     h  m  s  °     h  m  s  °     h  m  s  ° 

Addis Abeba            --      -      --      -      --      -   04:37:27  20   04:55:04  24 
Adelaide            22:16:01   4   22:34:08   7   01:30:59  30   04:27:00  27   04:44:58  26 
Algiers                --      -      --      -      --      -   04:37:56   1   04:55:38   4 
Al-Kuwayt              --      -      --      -      --      -   04:37:06  34   04:54:37  38 
'Amman                 --      -      --      -      --      -   04:37:38  25   04:55:12  28 
Amsterdam              --      -      --      -      --      -   04:37:12   9   04:54:51  11 
Athens                 --      -      --      -      --      -   04:37:50  16   04:55:26  20 
Auckland            22:15:25  24   22:33:27  25   01:29:01  28   04:25:08   7   04:43:17   4 
Baghdad                --      -      --      -      --      -   04:37:14  32   04:54:46  35 
Baku                   --      -      --      -   01:31:41   3   04:36:49  36   04:54:18  40 
Bangkok                --      -      --      -   01:32:17  36   04:32:15  76   04:49:46  79 
Barcelona              --      -      --      -      --      -   04:37:45   2   04:55:26   5 
Beijing             22:09:53  14   22:27:40  17   01:30:32  52   04:31:51  72   04:49:20  71 
Beirut                 --      -      --      -      --      -   04:37:37  25   04:55:10  28 
Beograd                --      -      --      -      --      -   04:37:36  16   04:55:11  19 
Berlin                 --      -      --      -      --      -   04:37:13  14   04:54:50  16 
Bern                   --      -      --      -      --      -   04:37:32   8   04:55:11  11 
Birmingham             --      -      --      -      --      -   04:37:07   5   04:54:47   8 
Blacktown           22:15:56  13   22:34:00  16   01:30:16  33   04:26:10  23   04:44:10  21 
Bogota              22:05:21  13   22:23:10   9      --      -      --      -      --      - 
Bombay                 --      -      --      -   01:32:50  13   04:35:10  54   04:52:39  58 
Brisbane            22:15:43  19   22:33:45  22   01:30:02  40   04:26:00  27   04:43:59  24 
Brussels               --      -      --      -      --      -   04:37:17   8   04:54:56  10 
Bucharest              --      -      --      -      --      -   04:37:31  20   04:55:06  23 
Budapest               --      -      --      -      --      -   04:37:28  16   04:55:04  19 
Cairo                  --      -      --      -      --      -   04:37:51  20   04:55:25  24 
Calcutta               --      -      --      -   01:32:22  28   04:33:47  69   04:51:16  73 
Caracas             22:04:37   9   22:22:26   5      --      -      --      -      --      - 
Christchurch        22:15:36  17   22:33:42  19   01:29:21  22   04:25:25   4   04:43:35   2 
Colombo                --      -      --      -   01:33:09  15   04:34:09  56   04:51:40  60 
Copenhagen             --      -      --      -      --      -   04:37:00  14   04:54:37  17 
Dacca                  --      -      --      -   01:32:15  30   04:33:37  71   04:51:06  75 
Damascus               --      -      --      -      --      -   04:37:36  25   04:55:09  29 
Dar-es-Salaam          --      -      --      -      --      -   04:36:48  14   04:54:30  18 
Delhi                  --      -      --      -   01:32:19  20   04:34:57  59   04:52:25  63 
Dublin                 --      -      --      -      --      -   04:36:59   4   04:54:40   6 
Glasgow                --      -      --      -      --      -   04:36:51   6   04:54:32   8 
Gorki                  --      -      --      -   01:30:34   7   04:36:25  32   04:53:56  34 
Guadalajara         22:06:04  45   22:23:44  41   01:25:20   1      --      -      --      - 
Guangzhou (Canton)  22:11:34   6   22:29:27  10   01:31:22  50   04:31:20  89   04:48:51  85 
Guatemala           22:05:36  32   22:23:19  28      --      -      --      -      --      - 
Hamburg                --      -      --      -      --      -   04:37:09  12   04:54:46  15 
Harare                 --      -      --      -      --      -   04:36:28   2   04:54:17   6 
Havana              22:04:38  27   22:22:20  23      --      -      --      -      --      - 
Helsinki               --      -      --      -   01:29:58   1   04:36:36  22   04:54:10  24 
Ho Chi Minh            --      -      --      -   01:32:06  41   04:31:28  77   04:49:01  78 
Istanbul               --      -      --      -      --      -   04:37:36  21   04:55:10  24 
Jakarta                --      -      --      -   01:32:28  33   04:30:44  61   04:48:22  61 
Jerevan                --      -      --      -      --      -   04:37:05  32   04:54:35  36 
Jerusalem              --      -      --      -      --      -   04:37:40  24   04:55:14  28 
Kabul                  --      -      --      -   01:32:05  15   04:35:39  52   04:53:06  55 
Kampala                --      -      --      -      --      -   04:37:27  11   04:55:08  15 
Karachi                --      -      --      -   01:32:37  10   04:35:46  50   04:53:14  54 
Katowice               --      -      --      -      --      -   04:37:19  16   04:54:55  19 
Khartoum               --      -      --      -      --      -   04:37:50  17   04:55:27  21 
Kiev                   --      -      --      -      --      -   04:37:07  24   04:54:41  26 
Kingston            22:04:37  21   22:22:21  17      --      -      --      -      --      - 
Kuala Lumpur           --      -      --      -   01:32:32  33   04:31:41  68   04:49:15  70 
Lima                22:06:54   9   22:24:49   5      --      -      --      -      --      - 
London                 --      -      --      -      --      -   04:37:12   6   04:54:52   8 

Lusaka                 --      -      --      -      --      -   04:36:44   1   04:54:33   5 
Lyon                   --      -      --      -      --      -   04:37:34   6   04:55:14   9 
Madrid                 --      -      --      -      --      -      --      -   04:55:25   1 
Manchester             --      -      --      -      --      -   04:37:02   6   04:54:43   8 
Manila              22:12:39  10   22:30:33  14   01:31:14  55   04:30:10  78   04:47:44  75 
Marseille              --      -      --      -      --      -   04:37:42   5   04:55:22   8 
Melbourne           22:16:03   7   22:34:10  10   01:30:39  28   04:26:35  22   04:44:35  20 
Mexico City         22:05:51  41   22:23:32  37      --      -      --      -      --      - 
Milan                  --      -      --      -      --      -   04:37:37   9   04:55:16  12 
Minsk                  --      -      --      -      --      -   04:36:59  22   04:54:33  25 
Monterrey           22:05:34  43   22:23:13  39   01:25:25   0      --      -      --      - 
Montreal            22:03:34  24   22:21:13  21      --      -      --      -      --      - 
Moscow                 --      -      --      -   01:30:30   4   04:36:38  28   04:54:10  31 
Nairobi                --      -      --      -      --      -   04:37:11  15   04:54:52  19 
Novosibirsk         22:07:12   1   22:24:59   3   01:30:39  27   04:34:37  51   04:52:05  53 
Omsk                   --      -      --      -   01:30:45  22   04:35:09  47   04:52:37  49 
Osaka               22:10:47  27   22:28:32  31   01:29:47  68   04:30:02  66   04:47:36  63 
Oslo                   --      -      --      -      --      -   04:36:42  15   04:54:19  17 
Ottawa              22:03:39  26   22:21:17  23      --      -      --      -      --      - 
Panama City         22:05:19  20   22:23:06  16      --      -      --      -      --      - 
Papeete             22:12:30  50   22:30:22  49   01:26:38  25      --      -      --      - 
Paris                  --      -      --      -      --      -   04:37:23   6   04:55:03   9 
Perth                  --      -      --      -   01:32:10  23   04:28:56  35   04:46:47  35 
Port Moresby        22:14:52  24   22:32:49  28   01:30:05  56   04:26:43  44   04:44:32  40 
Praha                  --      -      --      -      --      -   04:37:21  14   04:54:58  16 
P'yongyang          22:10:11  21   22:27:57  24   01:30:09  59   04:31:03  70   04:48:34  67 
Quebec              22:03:29  23   22:21:08  20      --      -      --      -      --      - 
Quito               22:05:57  15   22:23:47  11      --      -      --      -      --      - 
Reykjavik           22:03:25   5   22:21:07   4      --      -   04:35:54   4   04:53:36   6 
Riyadh                 --      -      --      -      --      -   04:37:11  32   04:54:43  36 
Rome                   --      -      --      -      --      -   04:37:47  10   04:55:26  13 
St. Petersburg         --      -      --      -   01:30:06   3   04:36:32  24   04:54:05  27 
San Jose            22:05:31  24   22:23:16  20      --      -      --      -      --      - 
San Juan            22:04:07  11   22:21:53   7      --      -      --      -      --      - 
San Salvador        22:05:34  30   22:23:18  26      --      -      --      -      --      - 
Santo Domingo       22:04:16  15   22:22:02  11      --      -      --      -      --      - 
Seoul               22:10:22  21   22:28:08  25   01:30:08  60   04:30:52  70   04:48:24  68 
Shanghai            22:10:57  15   22:28:46  19   01:30:39  57   04:30:58  78   04:48:30  75 
Shenyang (Mukden)   22:09:50  19   22:27:35  23   01:30:09  56   04:31:23  69   04:48:54  67 
Singapore              --      -      --      -   01:32:29  35   04:31:23  67   04:48:57  68 
Sofia                  --      -      --      -      --      -   04:37:39  17   04:55:14  20 
Stockholm              --      -      --      -      --      -   04:36:43  18   04:54:19  20 
Stuttgart              --      -      --      -      --      -   04:37:26  10   04:55:04  13 
Suva                22:14:29  41   22:32:24  43   01:28:14  44   04:24:51  15   04:42:56  11 
Svalbard            22:04:32  11   22:22:13  11   01:28:51  14   04:35:05  22   04:52:41  23 
Sydney              22:15:56  13   22:34:00  16   01:30:15  33   04:26:09  23   04:44:09  20 
T'aipei             22:11:37  13   22:29:27  17   01:30:52  58   04:30:39  81   04:48:11  77 
Taskent                --      -      --      -   01:31:41  17   04:35:37  51   04:53:04  54 
Tehran                 --      -      --      -   01:31:59   2   04:36:49  38   04:54:19  41 
Tel Aviv               --      -      --      -      --      -   04:37:41  24   04:55:15  27 

Tianjin             22:09:59  14   22:27:46  17   01:30:32  52   04:31:45  73   04:49:14  72 
Tokyo               22:10:41  31   22:28:25  35   01:29:31  70   04:29:47  63   04:47:22  59 
Toronto             22:03:48  28   22:21:27  25      --      -      --      -      --      - 
Vancouver           22:05:48  55   22:23:22  53   01:25:53  24      --      -      --      - 
Ulaanbaatar         22:08:45  10   22:26:31  13   01:30:31  43   04:32:54  65   04:50:23  65 
Victoria            22:11:41   6   22:29:34  10   01:31:21  51   04:31:13  88   04:48:44  84 
Vienna                 --      -      --      -      --      -   04:37:27  14   04:55:04  17 
Volgograd              --      -      --      -   01:31:04   3   04:36:46  32   04:54:17  35 
Willemstad, CuracÉ  22:04:36  11   22:22:24   7      --      -      --      -      --      - 
Winnipeg            22:04:28  40   22:22:04  37   01:26:01   8      --      -      --      - 
Xi'an               22:10:15   6   22:28:05  10   01:31:06  47   04:32:14  78   04:49:43  78 


Read more about Venus Transit at the Venus transit FAQ page

Tuesday, June 5, 2012

Viewing the Venus Transit

Viewing the Venus Transit requires special preparations. The transit is on the face of the sun, so direct viewing is impossible. Remember that direct viewing of the sun with the eyes is dangerous and doing it with an optical aid such as binoculars or a telescope may cause permanent damage and blindness. Do not use improvisations such as old floppy disks, old films etc.
The instructions are also suitable for a Solar eclipse observations. 

After this warning here are some options to view the Venus transit.
Solar Eclipse Glasses
  1. Get special solar eclipse glasses. These are special glasses, with special filters which block almost 99.99% of the sun light. Such glasses are not expensive, and will be very useful for future solar eclipses (there will be a full solar eclipse in 2017 in the USA). However, such glasses are to be used with the eyes only, and not through a telescope or binoculars!
  2. If you have a telescope you might want to consider to purchase a Solar Telescope Filter for it. There are generic filters which are suitable for many telescopes and there are vendor specifics filters for the vendor brands. You can buy at Amazon or at your local dealer. These filters are attached to the telescope, in front of it and block the light BEFORE it enters the telescope. Such filters MUST NOT be used instead of an eyepiece. The light from the sun must be blocked before it is concentrated by the telescope (the filter is not strong enough to block the light after the telescope concentrates it). During the observations make sure that the filter is strongly attached and that no one removes it by mistake (especially when you are doing an observation with a group of people).
  3. If you are really into solar viewing, you should consider purchasing a dedicated solar telescope. Such telescopes as the Coronado PST are dedicated and safe for solar viewing and are useful to observe other interesting solar phenomena such as the sun prominence.
       
  4. If you have a telescope and you want to project the image to a large audience you can use the projection method. Basically you project the image of the Sun to a dark surface (make it in the shade) and focus. Sunspots are very visible this way. This method is appropriate for small refractors and Newtonian telescopes, but not for SCT telescopes. If you are not sure how to do it or if it is suitable for your telescope do not do it! Personally, I do not like this method very much since I think that if you already have a telescope, it is a very little investment to buy the filter. Take note that the intensity of the sun light may harm the telescope as it creates heat which can harm the plastic and the optics so do it at your own risk. Also make sure that no-one ever tries to look through the telescope at the sun. Full instructions are here
  5. You actually don't have to own a telescope to project the sun. You can build a great homemade pinhole projector from simple boxes. You will get a small image of the sun and you will be able to see a dark spot on it.
  6. If you do not have the solar glasses nor a telescope, join your local astronomy club. The transit is a major event and professional observatory and local amateur groups will provide the means for the public to view the transit. 
  7. Join a live web cast of the event. Many observatories from around the globe will host live cover of the event. You will be able to view it safely from your home. However, I think that this is the less preferred option to view the transit (just one step away from not viewing it at all) as there is no replacement for viewing with your own eye.


Projecting the sun through a telescope

Where is the 2012 venus transit visible

The transit of Venus is a very rare event. The next transit will happen in the 5th or 6th of June (depending on your time zone). Do not miss the opportunity to see this event.


Luckily the 2012 Venus transit will be visible from most of the world. In any given moment of the transit, people on the entire half of earth which face the sun will be able to see the transit. The duration of Venus transit is quite long, 6 hours, which means that many other  areas will see part of the transit, and only people on about a quarter of earth will not see any part of the transit.  Thus, Venus transit is going to be a real global event!

Visibility map of the 2012 Venus Transit
Visibility map of the 2012 Venus Transit
Let's see the 2012 map above. From the green areas the entire transit is visible from its beginning to its end. These areas include most of China, east Australia, east Russia and Alaska. Not bad. The Yellow areas are places which only part of the transit will be visible. In North America, the transit will be visible until the sun sets on June 5th. The other yellow areas - Europe, Israel, east Africa, the middle east and most of south Asia the transit will be visible immediately on June 6th Sunrise (when the transit is already in the middle).
However, people in he red area will not see the transit at all. Most of this red area is in the Atlantic ocean, but major parts of South America and west Africa, together with Portugal will not see the transit at all! Of course, people in these ares may use live broadcasts to take part in this event.

More information
What is the Venus Transit
Venus transit timetable


Sunday, June 3, 2012

Carnival of Space #252

Hi all,
This is the week that for the last eight years, astronomers all over the world have waited for. After this week we will wait another 105 years, before the rare celestial event of Venus Transit will happen again. It is only suitable for "The Venus Transit" site to host the "Carnival of Space" in this special week. The site began as a dedicated site to the Venus transit but become my site for general astronomy articles, please browse and enjoy it. The best place to start is with the Venus Transit FAQ!

Carnival of Space
Carnival of Space - from mygalaxies.co.uk

Also, I will be happy to receive reports of your observations and I encourage everyone who has a solar telescope to organize a public event in his local town or school. You can publish your event in advance, or just stand in a public place with your telescope and offer people to look. I am organizing such observation at my home town: "Givat Shmuel" and I hope that many will attend.

Many "Carnival of Space" writers sent articles about Venus, please read them:

Amy Shira Teitel from Vintage Space writes a fascinating article about a manned mission to Venus. When NASA had a bottomless budget, nerves of steel, and surplus Apollo hardware, Venus became a popular target. In 1967, the space agency entertained the possibility of sending men on a Venus orbital mission.

Ian Musgrave from Astroblog sends detailed instructions on how to project the Venus transit through binoculars. Make sure you read the instructions carefully, and remember never to look directly at the sun.

If you need a little rest from reading, turn up your speakers and listen to the following Venus transit podcast from Steve Nerlich the editor of Cheap Astronomy.

Looking for information on how to view Tuesday's Transit of Venus? Ray Sanders at the "Dear Astronomer" blog has a quick "transit guide" round-up

Astronomers around the world are planning observations, and one team is traveling to Easter Island in an attempt to reproduce the measurements first made/proposed by Edmund Halley. Ray Sanders describe how you can help astronomers collect Venus transit data!

Follow Links Through Space in their journey to capture the Transit of Venus. Astronomy Club Toutatis visit Enontekiö, Lappland to photograph the event and enjoy the last transit of Venus of our life time.


If you had enough from Venus, lots of other things are happening in the astronomy and space industries. Please read on to be updated on the recent news items.

Charis Dann from weirdwarp summarize Space X mission to the ISS.

Brain Wang from Nextbigfuture takes us into the future of Space-X and writes about the upgraded Falcon 9 v1.1 rocket which will be more powerful and provide better abilities and maybe manned missions as well to the ISS.

And for a little detective story from Nancy Atkinson and UniverseToday. Astronomers and students from the University of Minnesota hoping to search for radiation left over from the Big Bang instead spent several days last week looking for their telescope – a 6,000 lb (2729 kg) behemoth of a science experiment. Just how does a telescope that big go missing?



Paul Gilster from Centauri Dreams looks at the question of whether our civilization would be detectable from another star, assuming a level of technology not much higher than our own. The upcoming "Square Kilometer Array" (SKA) may help make detecting other civilizations more likely, but will it be as powerful as some proponents suggest?

Paul Scott Anderson  from the Meridian journal moves our focus to our outer planet neighbor  Mars. The idea that Mars used to be a “water world” and sort of like a smaller version of Earth in many ways is now pretty much accepted among planetary scientists; the debate continues however as to just how wet it was and for how long. The answer has direct implications for the possibility of life ever having started there. Two more pieces of the puzzle now suggest, or reinforce the notion, that Mars was indeed a much wetter place than the cold, dry desert we see today.

Mike Simonsen from Simostronomy gets several astronomy magazines, but one of his favorite guilty pleasures in life is the time he spends every other month with the Journal of the British Astronomical Association. Mike says that it is so well done it is worth the price of BAA membership just to get this journal. Mike sends a poem dedicated to paper in general and to the JBAA in particular.


Monday, May 21, 2012

Refrigerator Magnets


How many time has it happened that you came home and find magnets stuck to your door.  Instead of throwing them away or immediately putting them on your fridge , lets try and learn something about them. Here is a short, easy and fun-to-do scientific experiment with refrigerator's magnets. For our experiment we need two magnets and we will try to stick them together in different ways.

Watch the video to understand what we are going to do and then read the explanations





Try and repeat the experiment shown in the video. Put the magnets together and try to slide one of them up and down. There can be three possibilities:
1) The magnet will slide smoothly
2) The magnet will jump and make a noise
3) The magnets will not hold very well

If the magnets do not hold well, turn one of them 90 degrees and try again, than you will have either option 1 or 2 depending on the direction you choose to slide the magnet (up-down or left-right). Change the direction of sliding and the direction of one of the magnets until you encounter all three possibilities given above.


So why is this? A full explanation of magnetism will require to go into a detailed explanation about magnetic fields and is really unnecessary. We will focus just on remembering that a magnet has its end referred to as the north and south poles. When a north pole is attached to a south pole, the magnets will pull each other, but when attempting to attach a north side to a north side, the magnets will reject each other.
The refrigerator magnets have indeed the two poles but the poles are lined out one next to the other, like columns, within the magnets. Look at the illustration below to see how it works.
Refrigerator Magnet
Refrigerator Magnet is built from strips of North and South next to each other
So when we attached our refrigerator magnets in a way that a north meets south, they  attach strongly. In one direction (for example: up-down) we can slide them with ease, since even if we slide them, the south pole is still on a north pole, but when we try to slide them in the other direction (left-right), it happens that the north pole meets another north pole which immediately rejects it until it finds the next south pole, this makes the non-smooth movement and the loud noise.
When the magnets are attached in the other direction, the north poles meet north and south poles all the time. This creates rejection of the magnets and attracts force which more or less eliminates each other and the magnets do not stick, or connect very loosely.