Astronomers have used the ESO's Very Large Telescope to measure the stellar vibrations of a nearby star. The team studied Alpha Centauri B, one of our closest neighbours - only 4.3 light-years away - and relatively similar to our own Sun. Churning gas in the star's outer layers creates low-frequency sound waves that bounce around inside the star and cause it to pulse in and out slightly. The star only changes about a dozen metres every four minutes, but that makes enough of a change in the wavelength of light we see to be able to detect it.

NASA's Grace Earth observation satellite has created the first, comprehensive survey of the entire Greenland ice sheet. The spacecraft found that the volume of ice is decreasing by 162 cubic kilometres per year (39 cubic miles), which is higher than all previously published estimates. This ice melt is contributing 0.4 millimeters (.016 inches) per year to global sea level rise. Grace was also able to measure detailed changes in the surface of the sea floor after the Sumatran earthquake and resulting tsunami that happened almost a year ago.

Tom Gwilym took this picture of M42 from his backyard observatory in Renton, WA. Tom used Orion 80ED with Canon 10D DSLR and IDAS light pollution filter.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Mike Salway took this collection of planetary images over the year 2005 . Mike's planetary imaging includes pictures of Mars, Saturn and Jupiter.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

NASA is in the final stage of preparations for the launch of its New Horizons spacecraft, destined to lift off for Pluto in January 2006. If all goes well, New Horizons will blast off January 17, 2006 atop an Atlas V rocket; the launch window extends until February 14, 2006. The spacecraft will make a gravity slingshot past Jupiter in 2007, and arrive at Pluto as early as mid-2015.

The physical constants of the Universe are thought to have remained unchanged since the Big Bang; many predictions made by cosmologists depend on it. An international team of researchers are using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to see if things really have gone on unchanged for billions of years. They're looking to measure two universal constants: the ratio of mass between protons and electrons, and something called the fine structure constant.

Equality is a rallying call for many. The emancipation of women gave ladies the right to vote, obtain education, achieve gainful employment and have an equal chance at being a national leader. However, this freedom doesn't extend to all nations nor to all industries. In the book Women in Space by David Shayler and Ian Moule, we read how women have made many startling contributions to aerospace and are also well on their way to being an accepted part of space programs. By listing their many achievements, the authors demonstrate that women can equally contribute, but only if and when society lets them.

This beautiful photograph shows Saturn's moon Rhea, partially obscured by the rings. The material surrounding the ring is probably on the planet's equatorial plane, extending farther out from the ring's main core. This image was taken on Oct. 30, 2005, at a distance of approximately 689,000 kilometers (428,000 miles) from Saturn.

Instruments on board Cassini have confirmed that Saturn's faintest ring is being created by particles emitted by its icy moon Enceladus. Scientists are amazed that this tiny, supposedly dead moon has such active volcanoes. Some unknown process is heating up the interior of Enceladus, especially near the southern pole, causing this plume of ejected material. Most of the larger particles probably reimpact the moon, but the smaller ones are pushed into orbit around Saturn by sunlight.

Greetings, fellow SkyWatchers... I hope you have your shopping done, because this is going to be one exciting week! We'll start off with awesome barred spiral NGC 1300 and move on to study both a white and red dwarf star. We'll pass through the Delta Arietids meteor stream, reach Winter Solstice and search out new cluster Collinder 62. The next morning we'll pass through the stream of comet 8/P Tuttle and hunt down Mercury. But the early morning excitement hasn't ended as the Moon will occult Beta Virginis and Venus comes to a standstill. Not enough? Then hang on as we explore multiple system Theta Orionis and watch as asteroid Vesta slides by bright star Delta Geminorum. Still up for more? Then enjoy a very special Christmas morning as the Moon occults Spica and the night brings around the one and only "Christmas Tree Cluster!" It's time to dance among the winter stars, because...

Here's what's up!

NASA's Chandra X-Ray Observatory has taken a new photograph of SN 1006; a supernova that appeared in the sky in 1006, and blazed more brightly than Venus. We now know that SN 1006 announced the death of a star located approximately 7,000 light years from Earth. It's likely that a white dwarf star was siphoning matter away from a companion star. When its mass exceeded the limit of stability, it exploded.

A study of ice samples extracted from deep underneath Greenland's ice sheet could help scientists recognize methane-producing bacteria on Mars. ESA's Mars Express spacecraft recently turned up evidence of methane in the martian atmosphere. The source of this methane could be from a class of bacteria called Archaea. Although the best place to look for microbes would be from ice several hundreds of metres down, there should also be meteor craters where rock has been recently exposed.

Like all spiral galaxies, our own Milky Way has magnificent spiral arms. We're just inside the galaxy, so we don't get a good view of them. An international team of radio astronomers have revised the distance to the Milky Way's Perseus spiral arm. They used a simple method called triangulation, where the angles to various stars are measured when the Earth is at opposite sides of its orbit. The previous estimates are probably off because the stars are moving more quickly than astronomers realized, which added errors to the calculations.

This photograph shows two of Saturn's ring shepherd moons surrounded by halos of icy particles: Prometheus (at left) and Pandora (at right). Prometheus tugs at Saturn's rings pulling a stream of particles towards it as it orbits the giant planet. Cassini took this image on October 29, 2005 when it was approximately 459,000 kilometers (285,000 miles) from Pandora and 483,500 kilometers (300,500 miles) from Prometheus.

An international team of astronomers have analyzed a recent short gamma-ray burst, and they think it's the last scream of a neutron star being gobbled up by a black hole. The burst was discovered on July 24, 2005 by NASA's Swift satellite, and then astronomers performed followup observations with a variety of instruments. The length of the explosion and the wavelengths of radiation emitted have led astronomers to the conclusion that it had to be a neutron star colliding with a black hole.

Astronomers have discovered a dusty disk around a young star that could be in the process of forming new planets. The star, which is approximately the size of our own Sun, was observed using NASA's Spitzer Space Telescope. The star, known as HD 12039, is about 30 million years old; the age at which astronomers believe the terrestrial planets in our Solar System had nearly formed. Based on Spitzer's analysis to date, it looks like only 1-3% of young Suns have a disk like this surrounding them.

With Christmas approaching, I just wanted to give you a final reminder about the Year in Space 2006 calendar. This 144-page spiral-bound desk calendar has 53 full-colour space photographs, so you can gaze into infinity as you plan your week. It's filled with space trivia, sky events, daily Moon phases, and additional calendars. Universe Today readers can save at least 27% off the suggested retail price and pay only $10.95 USD by ordering online. There's free shipping in the U.S., and deeper discounts for multiple copies. Click here to visit their website.

Fraser Cain
Publisher
Universe Today

P.S. And congratulations to Andrea from Madison, Wisconson who won the calendar giveaway I did last week. Nice going!

Rick Gatley took this picture of a contrail shadow from Texas. This picture was taken the cockpit of a BeechJet 400A flying westbound at 40,000 feet over the Texas coast.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.