The Solar and Heliospheric Observatory (SOHO) is celebrating its 10th anniversary of operations on December 2nd, 2005. Over the course of these 10 years, SOHO has revealed the nature of the Sun's atmosphere, the links between its magnetic fields and coronal mass ejections, and even discovered more than 1,000 comets. Scientists even figured out how to use SOHO to probe the far side of the Sun.

Telescopes from around the world are constantly scanning the skies searching for potential Earth-crossing asteroids. The majority if these objects pose little to no threat to us, but the potentially devastating space rocks are out there. The European Space Agency is working on a mission called Don Quixote which would attempt to shift the orbit of an asteroid to understand the mechanics of this kind of operation.

Theoretical physicist Dr. Lawrence M. Krauss from Case Western University and author of Hiding in the Mirror: The Mysterious Allure of Extra Dimensions, from Plato to String Theory and Beyond has agreed to answer questions from the Bad Astronomy/Universe Today forum. If you've got puzzling questions about physics, multiple dimensions, or any of his books, follow this link to the forum and post a question. We'll gather up the best questions and pass them along to Dr. Krauss to answer. I'll post his answers back in Universe Today when I get them.

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Now on its way to our nearest planetary neighbour, Venus Express tested its VIRTIS optics system by taking pictures of the Earth and the Moon. ESA controllers ran the spacecraft through a commissioning phase to test all of its scientific instruments. It took pictures of the Earth and the Moon when it was 3.5 million kilometres away. The VIRTIS instrument is also on board the Rosetta spacecraft, which also took images of our planet. ESA scientists will be able to compare the images to ensure the instrument is working perfectly.

The newly installed AMBER instrument on ESO's Very Large Telescope Interferometer combines the light from two or three 8.2 metre telescopes creating a virtual telescope 40 - 90 metres across (131 - 295 feet). It was used to observe a young, newly forming star called MWC 297, and discovered that it's surrounded by a proto-planetary disc which is strangely truncated near the star.

In this Cassini image of Mimas perched in front of Saturn's moons, you can clearly see its giant crater Herschel. The 130-kilometer (80-mile) crater makes the moon look like the Death Star from Star Wars. Cassini took this image on October 13, 2005 when it was approximately 711,000 kilometers (442,000 miles) from Mimas.

This photograph of a fractured and crater-scarred Dione was taken by Cassini on October 11, 2005, when the spacecraft was only 19,600 kilometers (12,200 miles) away from the moon. Most of the craters in this image have bright walls and dark deposits of material on their floors. Rock slides on the surface of Dione can reveal cleaner ice, while the darker materials accumulate in lower areas.

Bob Christmas took this picture of Mars and the Pleiades on October 3, 2005 from Ontario, Canada. Bob used a Canon 135mm telephoto lens set at f/4.

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.

Thomas Davis took this picture of the M78 Orion on the 12th of December, 2004 from Inkom, ID. Thomas used Astro-Physics 155 EDF f/7 refractor.

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.

Amateur astrophotographer R Jay GaBany took this picture of the Dumbbell Nebula Nova that was discovered on the 17th - 18th, August 2005. GaBany worked with Wolfgang Renz, of the BAV (German Workgroup for Variable Stars), to provide imagery that confirmed the discovery.

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.

Officials from the Japanese space agency (JAXA) announced yesterday that Hayabusa successfully touched down on asteroid Itokawa last weekend, bounced at least once, and spent 39 minutes "resting" on the surface. It then launched back up into space again. Unfortunately, it failed to drop equipment that would allow it to collect samples from the asteroid's surface. Hayabusa will head back to the potato-shaped asteroid on Friday and attempt another landing.

Since the Moon only has a slight tilt, some of its mountains are bathed in eternal sunlight, and would make ideal places to put solar panels to power a future moon base. The European Space Agency's SMART-1 spacecraft is currently mapping the Moon, and one its missions is to identify some of these peaks of eternal light. These peaks could also provide a very stable environment, always approximately 20-degrees below zero Celsius. There are probably also craters in the region which are in eternal shadow, and could contain water ice.

Cassini took this amazing image of Saturn's moon Dione on approach to its recent October 11, 2005 rendezvous; Saturn itself sits in the background. Dione is much darker on its western side in this image, and you can see the bright wispy fresh canyons right at the edge. Cassini took this image when it was approximately 24,500 kilometers (15,200 miles) from Dione.

NASA's Spirit rover recently celebrated its one year anniversary on the surface of Mars... that's one Martian year. Spirit has now been exploring the Red Planet for more than 669 days. Not bad considering the rovers were only expected to perform for 60-90 days until their solar panels became so clogged with dust they wouldn't function. And even after surviving more than 7-times their expected lifetimes, Spirit and its twin Opportunity are still going strong, and should be returning much more science.

Researchers from the University of Colorado at Boulder think they've found evidence that the very early Earth had continents soon after the planet formed, overturning theories that the planet was Moon-like, or covered with oceans. The team analyzed a rare element called hafnium in ancient minerals from the Jack Hills in Western Australia. It showed that continental crusts had formed 4.4 - 4.5 billion years ago, and were then recycled into the Earth's mantle.

Researchers are finding that the mysterious dark energy found to be accelerating the expansion of the Universe is remarkably well predicted by Einstein's cosmological constant. Einstein originally added this constant to balance out the gravitation of the Universe, but threw it out after seeing evidence of the Big Bang. An international team of researchers has performed the Supernova Legacy Survey, and found that it calculates dark energy to be within 10% of Einstein's prediction.

If you're going to be traveling by airplane, take a look out the window; you might be amazed. On the side opposite to the Sun, you could see the shadow of the airplane in the clouds, and shimmering rings of colour surrounding it. Look out the sunward side, and you might see ice halos - arcs of light caused by ice crystals in the high clouds. And don't forget to look up. You're above much of the Earth's atmosphere, and should be able to see a clearer view of the night sky than from the ground.

In this Cassini image of Saturn's moon Dione, you can see the wispy features that run across its surface. It's also possible to see the craters Dido and Antenor near the moon's terminator at lower left. Cassini took this image on October 9, 2005 from a distance of 1.8 million kilometers (1.1 million miles).

NASA's Mars Reconnaissance Orbiter fired its main engine for 20 seconds on Friday, fine-tuning its course towards the Red Planet. The spacecraft is schedule to reach Mars on March 10, 2006. Since its August 12 launch, the spacecraft has traveled about 60% of the distance between Earth and Mars, and it will make 4 more adjustments before arriving at Mars. Once it does arrive, MRO will spend about half a year adjusting its orbit before beginning its science phase.