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April 2011

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This month the highlight news is the launch of the Eratosthenes Project Eratosthenes. Eratosthenes Project is expected to join schools all around Europe (and eventually world-wide) on an experiment to achieve a measurement of Earth's Perimeter on June 21st, 2011.

On this month's issue you can find links to astronomy news the that were published on our EAAE News site in the "It happened last month" section.

On the "Astronomical Observations" section we invite you to the observation of this month's "star of the night" which is planet Saturn. If you are more skilled take your chance with NGC2683 in Lynx.

On the " Software and Internet Astronomy" section we will present you the LSST, to have first light in 2014 and a must for the next decade of teachers.

As usual we also have some activities in the Students Corner and we have selected a beautiful astronomical picture of Rho Ophiuchi for this months "Picture Gallery".

We wish you all clear skies during the next month.

The EAAE Webteam

Here comes the 2011 Eratosthenes Project campaign

Once again in 2011 the EAAE is proud to announce the opening of the campaign to reproduce the Eratosthenes Experiment at a global scale. Following the 2010 campaign's success next this activity will be repeated at the next European Summer Solstice on 21st of June 2011.

Every school in Europe is invited to participate in this global experience in order to measure the Earth circumference. With the only help of the shadow projected by a stick, the participating students will be able to repeat the Erastothenes calculation. Moreover, a video conference will allow all participants to see how the activity is performed in the Bibliotheca of Alexandria, the mythic place where this measure was done by the greek mathematician more than 2000 years ago. All information concerning the event will be held on

A screenshot of the project's webpage.

Materials that will help the schools to reproduce the Eratosthenes Experiment locally where created and are also available on the website as well as calculators to help schools confirm their calculations based on their measurements.These calculators can also be used by small children school to make the calculations that the children cannot perform because the don't have the mathematical skills to do them.

The project intends to allow schools to reproduce the Eartothenes Experiment locally.


The Eratosthenes website also has links to several complementary Didactical Materials that can be used by teachers when preparing this project or for many other purposes. EAAE members, Anna Artigas and Guido Robotti, will coordinate the 2011 campaign of the project.

The EAAE Eratosthenes Project

Last Month's highlights from EAAE News
Monday Tuesday Wednesday Thursday Friday Saturday Sunday

March 28th

March 29th

March 30th

March 31st

April 1st: Day 91 of the gregorian calendar.
In 1960, the United States launched their first meteorologic satellite, TIROS-1.

A crescent Moon can be seen 13º Eastwards from Venus at sunrise.

April 2nd: Day 92 of the gregorian calendar.
History: On this date in 1889,
the Harvard Observatory’s 13" refractor arrived at Mt. Wilson. Just one month later, it went into astronomical service at Lick Observatory, located at Mt. Hamilton. It was the largest telescopes in the World from 1908 to 1948 – it was 60" for the first decade, then upgraded to 100".

April 4th: Day 94 of the gregorian calendar.
In 1968, Apollo 6 was launched.
In 1983, Space Shuttle Challenger made its first flight up to Space.

Saturn is at opposition, which means it is opposite to the Sun in the sky rising around sunset and setting around sunrise. It is now also at its brightest for 2011.

April 5th: Day 95 of the gregorian calendar.
In 1973 the probe Pioneer 11 makes the first direct observations of Saturn.
In 1991 the Compton Gamma Ray Observatory was launched.
In 2007, a faint star in the constellation Bootes, the Herdsman, made astronomical history. A team led by the french Jean-Francis Donati and Claire Montau, caught the star Tau Bootis flipping its north and south magnetic poles while these astronomers were mapping the magnetic fields of stars. This was the first time a magnetic reversal was observed besides Sun. Try to find Tau Bootis tonight.

April 7th: Day 97 of the gregorian calendar.
In 1991, the Compton Gamma Ray Observatory was activated.
In 2001 the first sucessuful flight of Proton M.
In 2001 the probe Mars Odyssey was launched.
Observations: This night the Moon is right of Adebaran and the Hyades.

April 8th: Day 98 of the gregorian calendar.
In 1964, the unmanned mission Gemini 1 was launched.

Observations: Try to make a picture of Saturn with your telescope. Have you considered using a webcam? Try to find out how it can be done.

April 9th: Day 99 of the gregorian calendar.

In 1994, the STS-59 mission of space shuttle Endeavour was launched.

Observations: As Moon approaches first Quarter, there are gret opportunities to make fabulous pictures of it.

April 10th: Day 100 of the gregorian calendar.
History: In 1981, the first launch attempt of the mission STS-1 (the first mission of a Space Shuttle) was aborted in the last moment due to computer failure.

Try to make an image of the Com Star Cluster. We talked about it on April's newsletter last year.

April 13th: Day 103 of the gregorian calendar.
"Houston, we have a problem". These were the words of the astronaut Jack Swigert on this day in 1970 after the oxygen tank number 2 of the service module of the Apollo 13 mission exploded.The astronomers were able to return safely to Earth after emergency procedures with perfect coordination between mission control and the crew.

Regulus 6º above the Moon.

April 15th: Day 105 of the gregorian calendar.
Try to find the names of the stars of the Big Dipper. There is a star called Mizar that has a star called Alcor next to it. These two stars that form a false binary system are sometimes called the "Horse and Rider," and the ability to resolve the two stars with the naked eye is often quoted as a test of eyesight, although even people with quite poor eyesight can see the two stars. Can you see them?

April 18th: Day 108 of the gregorian calendar.
Follow the tail of the Big Dipper and you will find the star Arturus (Alpha-Bootes). If you continue the arch you will find the star Spica (Alpha Virgo).

April 20th: Day 110 of the gregorian calendar.
In 1972, the Apollo 16 mission lands on the Moon and becomes one of the six successful manned missions to the Moon.

April 21st: Day 111 of the gregorian calendar.
In 2002, a solar eruption provides an excellent data acquisition opportunity for the probes SOHO, TRACE e RHESSI and test the Lin & Forbes model for CMEs (coronal mass ejections).

April 23rd: Day 113 of the gregorian calendar.
In 1967, the Russian mission Soyuz 1 was launched.

Though less meteors are expected, as the Moon comes up later you might be able to see some fireballs of the Lyrids tonight.

April 25th: Day 115 of the gregorian calendar.
In 1983 the Pioneer probe passed the orbit of Pluto.
In 1990, astronauts of the Space Shuttle Discovery (STS-31) repaired the Hubble Space Telescope.

Moon at Last Quarter at 02h47 (UTC).

April 26th: Day 116 of the gregorian calendar.
In 1920 the Shapley-Curtis debate about the nature and distance of nebula was held at the National Academy of Sciences, Washington, D.C..
In 1933 Arno Penzias was born. He was the co-discoverer of the Cosmic Microwave Background with Robert Wilson.

April 28th: Day 118 of the gregorian calendar.
:In 1903, M. Wolf discovers asteroid Iolanda (509).

Take the night to try to make a nice picture of Saturn with your telescope.

April 30th: Day 120 of the gregorian calendar.
In 1006, a very bright supernova was observed by Chinese and Egiptian in the constellation of Lupus.

Four planets are below the thin crescent Moon at eastern horizon at sunrise.

May 1st

Saturn and NGC 2683: For the beginners and for the skilled

On April 4th, 2011, at midnight (UTC), the Earth is precisely between Saturn and the Sun. When this happens to a planet we say that the planet is in opposition, therefore Saturn is in opposition.

Saturn is the faintest of the bright planets (Venus, Mars, Jupiter and Saturn) so you need good conditions to see it in all its glory. When a planet is in opposition you can observe it all night long. That means April 2011 presents the best time of the year to see Saturn and its rings because at opposition the planet is also at its closest to Earth and is as bright as possible in our sky.

Saturn is the only visible planet to grace the evening sky all through April and May 2011. Throughout April, Saturn stays out nearly all night long, and sets in the west at dawn. At about the time that Saturn sets, the other four visible planets – Mercury, Venus, Mars and Jupiter – will be rising in the east which will also give observational opportunities.

The Spring Triangle stretches across the eastern sky around 10 p.m. last night. It's formed by the star Arcturus (upper left), Saturn (top right) and Spica (below Saturn). Photo: Bob King

Saturn is now easy to find, because it’s near the bright star Spica, the alpha star of the constellation Virgo. If you go outside after sunset, and look between east and southeast you should see two bright objects. The slightly brighter one which is higher in the sky is Saturn.

Natural Saturn On The Cassini Cruise
Credit: Hubble Heritage Team (AURA/ STScI/ NASA)
(Click on the image to see a bigger image)

Now here is the hard one: NGC 2683.

NGC 2683 is an unbarred spiral galaxy discovered on February 5, 1788 . It was discovered by William Herschel and afterwards nicknamed the "UFO Galaxy" by the Astronaut Memorial Planetarium and Observatory. From Earth it is viewed nearly edge-on and it is located between 16 to 25 million light-years away. It is receding from Earth at 410 km/s (250 mi/s), and from the Galactic Center at 375 km/s (233 mi/s). The reddened light from the center of the galaxy appears yellowish due to the intervening gas and dust located within the outer arms of NGC 2683.

You will need a large tescope to have a good image of NGC 2683. To take an image like the image bellow you will need a telesocope with an aperture above 12''. Preferably you can use an online robotic telecope with your class to do this. Specifications can be found here.

NGC 2683
Adapted from EarthSky.
(Click on the image to see a bigger image)

To find NGC2683's location in a skymap click here.

Wikipedia - Saturn
Wikipedia - NGC2683


LSST - Large Synoptic Survey Telescope

New windows on the Universe will be here in 2014

Proposed for "first light" in 2014, the 8.4-meter LSST will survey the entire visible sky deeply in multiple colors every week with its three-billion pixel digital camera, probing the mysteries of Dark Matter and Dark Energy, and opening a movie-like window on objects that change or move.

Rendering of the Large Synoptic Survey Telescope (Credit: Wikipedia)

Under development since 2000, the LSST is a public-private partnership. This gift enables the construction of LSST's three large mirrors; these mirrors take over five years to manufacture. The first stages of production for the two largest mirrors are now beginning at the Mirror Laboratory at the University of Arizona in Tucson, Arizona. Other key elements of the LSST system will also be aided by this commitment.

The LSST will be constructed on Cerro Pachón, a mountain in northern Chile. Its design of three large mirrors and three refractive lenses in a camera leads to a 10 square degree field-of-view with excellent image quality. The telescope's 3200 Megapixel camera will be the largest digital camera ever constructed.

Location of the Large Synoptic Survey Telescope (Image Credit: C. Claver, NOAO/LSST)

In January 2008, this project received $20M from the Charles Simonyi Fund for Arts and Sciences and $10M from Microsoft founder Bill Gates because the project has many features that are similar to their own lifetime activity.

After beginning its work over ten years of operations, about 2000 deep exposures will be acquired for every part of the sky over 20,000 square degrees. This color "movie" of the Universe will open an entirely new window: the time domain. LSST will produce 30 Terabytes of data per night, yielding a total database of 150 Petabytes. Dedicated data facilities will process the data in real time.

"What a shock it was when Galileo saw in his telescope the phases of Venus, or the moons of Jupiter, the first hints of a dynamic universe" Simonyi said according to the Brookehaven National Laboratory News. "Today, by building a special telescope-computer complex, we can study this dynamism in unprecedented detail. LSST will produce a database suitable for answering a wide range of pressing questions: What is dark energy? What is dark matter? How did the Milky Way form? What are the properties of small bodies in the solar system? Are there potentially hazardous asteroids that may impact the earth causing significant damage? What sort of new phenomena have yet to be discovered? "

"LSST is just as imaginative in its technology and approach as it is with its science mission. LSST is truly an internet telescope, which will put terabytes of data each night into the hands of anyone that wants to explore it. Astronomical research with LSST becomes a software issue - writing code and database queries to mine the night sky and recover its secrets. The 8.4 meter LSST telescope and the three gigapixel camera are thus a shared resource for all humanity - the ultimate network peripheral device to explore the universe" Gates said. "It is fun for Charles and me to be a team again supporting this work given all we have done together on software projects."

"The LSST will be the world's most powerful survey telescope. This major gift keeps the project on schedule by enabling the early fabrication of LSST's large optics and other long-lead components of the LSST system," said Donald Sweeney, LSST Project Manager.

LSST is designed to be a public facility - the database and resulting catalogs will be made available to the community at large with no proprietary restrictions. A sophisticated data management system will provide easy access, enabling simple queries from individual users (both professionals and amateurs), as well as computationally intensive scientific investigations that utilize the entire database. The public will actively share the adventure of discovery of our dynamic Universe and this will be good for schools too.

LSST webpage
Brokhaven National Laboratory News




Solar System Sudoku is an EAAE transformation of the famous Japanese Sudoku. You have to put on each the nine symbols on each row, each column and each of the nine small nine spaces squares. This means each one of the nine symbols has to appear nine times on the Sudoku puzzle.

Instead of numbers, in this new version we use figures of the nine major celestial objects of the solar system (Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune).

In this new interactive version just go on clicking on the empty cells until the object you want appears. Now you can play it interactively as many times as you want. When you finish you can start a new game.

Have fun!








Stellar Formation in the Rho Ophiuchi Cloud. Image credit: NASA, JPL-Caltech, WISE Team
(click on the image to see a bigger version)

This fantastic false-color composition was accomplished using WISE, the Wide-field Infrared Survey Explorer. The Rho Ophiuchi cloud complex is a dark nebula of gas and dust that is located 1° south of the star ρ Ophiuchi of the constellation Ophiuchus. At an estimated distance of 131 ± 3 parsecs, this cloud is one of the closest star-forming regions to the Solar System. This cloud complex covers an angular area of 4.5° × 6.5° on the celestial sphere and is one of the most active region of stellar formation in our vicinity. After forming along a large cloud of cold molecular hydrogen gas, young stars heat the surrounding dust to produce the infrared glow. Stars in the process of formation, called young stellar objects or YSOs, are embedded in the compact pinkish nebulae seen here, but are otherwise hidden from the prying eyes of optical telescopes. An exploration of the region in penetrating infrared light has detected emerging and newly formed stars whose average age is estimated to be a mere 300 000 years. That's extremely young compared to the Sun's age of 5 thousand million years.

European Association for Astronomy Education