Mars' moon Phobos casts its shadow across the surface of the Red Planet in this photograph captured by ESA's Mars Express. Phobos is only 27 kilometres by 22 kilometres in size (17 x 14 miles), and it orbits Mars once every 7.5 hours. To an observer on the ground, this eclipse would look similar to one on Earth; however, Phobos would only cover about 20% of the Sun's surface. And it would be over quickly - the shadow moves at 7200 km/h (4400 mph).

Cassini captured two of Saturn's moons in this image: Titan and Tethys. Titan is in the upper left, and is shrouded by a thick atmosphere that protects it from most impacts. Tethys, on the other hand, has no atmosphere, and has suffered numerious impacts, including the enormous impact that dug out the crater Odysseus. This image was taken on January 6, 2006, when Cassini was 2.7 million km (1.7 million miles) from Tethys, and almost double that distance from Titan.

ESA's Mars Express spacecraft has spotted evidence of auroras over the night time side of Mars. These auroras make v-shaped structures of accelerated electrons and ions, similar to what we see here on Earth. Mars doesn't have a planetary magnetic field, so the discovery of auroras came as a surprise; however, it does have magnetic regions - the remnants of an old planetary magnetic field. Since Mars is always lit from our vantage point here on Earth, it required a spacecraft to find the auroras, which are only detectable at night on Mars.

After 100 days of travel, ESA's Venus Express tested its main engine for the first time. The burn only lasted 3 seconds, and changed the spacecraft's velocity about 3 metres/second (10 feet/s). The engine test worked perfectly, and Venus Express was able to reorient itself after the burn, and correctly point its high-gain antenna back at Earth. The engine will be used again on April 11, when it will fire for 51 minutes, putting it into orbit around Venus.

According to new research published by NASA scientists, Greenland's glaciers are losing ice at an accelerating rate. In the period from 1996 to 2005, the island's glaciers doubled the amount of ice they're shedding annually into the world's oceans. This acceleration is due to a global rise in temperature. Once Greenland's glaciers are all gone, scientists estimate world sea levels will have risen approximately 7 metres (23 feet).

Our five senses are all we have to allow our brains to interact with the world outside our bodies. Space exploration relies almost entirely on one, the sense of sight. Space probes send us images of planets, moons and other objects which we then have to decipher as best we can. Richard Greenberg in his book Europa, The Ocean Moon uses recent images of Europa, together with our understanding of celestial mechanics and plate tectonics, to unravel this little moon's mysteries. For Europa's biggest mystery is whether it harbours life who may be looking right back at us from their own little world.

In this beautiful Cassini photograph perfectly lined up along Saturn's ringplane, it's possible to see three of the planet's moons: Dione is at the left, Prometheus is in the centre, and Epimetheus is on the right. This image was taken on January 2, 2006, when Cassini was 2.8 million kilometers (1.7 million miles) from Saturn.

Japan's recently launched Advanced Land Observing Satellite (ALOS) has sent back its first pictures of Earth - Mt Fuji and its surrounding towns. The satellite was launched on January 24, 2006, and it contains three onboard instruments for Earth observation. One instrument is called the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM). It's capable of taking many 3-D images quickly and accurately.

If humans are going to be spending longer periods in space, on the Moon, or even on Mars, it's just a matter of time before they'll need surgery. Can delicate surgery even be done in the weightlessness? Doctors from NASA and the Canadian Space Agency think so. They're working out a series of experiments where surgeons will attempt procedures in weightless situations, like underwater or in a special aircraft that simulates weightlessness. They believe that future missions will have at least one surgeon and several of the crew will be trained in surgical techniques as well.

At first glance, this hazy view of Saturn seems largely featureless, but if you look closely, you can see great oval-shaped storms churning through the planet's clouds. The lines extending away from the storms indicate that there isn't much horizontal mixing between layers. This photograph was taken on January 2, 2006 when Cassini was 2.8 million kilometers (1.7 million miles) from Saturn.

Spitzer has uncovered an unusual pair of colliding galaxies whose hearts are surrounded by tiny crystals that resemble crushed glass. These crystals look like sand, and were probably shed from massive stars before and while they exploded as supernovae. Although these crystals have been seen in the Milky Way, this is the first time they've been found outside our galaxy. They won't last long, however. Scientists think the crystals will get heated up again and again by multiple supernova blasts and eventually melt back into a shapeless form.

Astronomers have used the light from a distant quasar to discover a metal-rich hydrogen cloud that would have otherwise been invisible; the quasar is 9 billion light-years away, but the cloud is only 6.3 billion light-years away. By analyzing the spectrum of this galaxy, astronomers have discovered that it contains 4 times more metal than what's contained in our Sun. If more of these clouds are discovered, it might help account for why the Universe seems to contain less metal that cosmologists have predicted it should.

When NASA's Chandra X-Ray Observatory took this photograph of the supernova remnant Puppis A, it revealed a how a cloud of nebula is being torn apart by the shockwave from the supernova explosion. The oval structure of the cloud with an empty region inside, closely matches experimental simulations done here on Earth, where a shockwave blasts past a cloud of vapourized copper. The cloud briefly compresses, and then rapidly expands leaving a cavity inside.

NASA astronomers have discovered an unusual solar system about 500 light-years away where the inner planets are going one direction, and the outer planets are going in the opposite direction. This newly forming system is quite different from our own Solar System, where the planets and the Sun all turn in the same direction. It's possible that the system formed from two different clouds of material, which were rotating in opposite directions.

Scientists are tracking a gigantic electrical storm raging on the surface of Saturn. This storm is the size of the United States, and the most powerful of its type ever seen. The origin of these storms is unknown, but researchers think it might have something to do with Saturn's warm interior. Cassini is expected to get much closer to Saturn in the next few weeks, so scientists will get a much better view.

A team of French scientists have successfully recreated the structure of primitive interstellar particles in their laboratory. This material is a silicate glass that contains embedded metal and suphides, and astronomers believe it's created in protostellar nebulae. The team heated up particles of olivine under high vacuum and temperatures ranging between 500 to 700ºC, and the resulting material closely matched this interstellar dust. This helps scientists understand some of the processes that occur in stellar nebulae.

Cassini was only 14,500 km (9,000 miles) from Saturn's moon Telesto when it took this photograph. Telesto is tiny, only 24 km (15 miles across), and it appears to be covered in fine, icy material that obscures ancient meteor strikes. This is quite different from many of Saturn's other moons, which look quite pockmarked in comparison.

Researchers at the University of St. Andrews and the Free University of Brussels think they have a solution that "fine-tunes" Einstein's groundbreaking theory of gravity to help account for the effect of dark matter. Dr Hong Sheng Zhao and Dr Benoit Famaey have created a new formula that allows the strength of gravity to vary over galactic distances, perfectly matching observations made by astronomers.