Cassini captured this image of Saturn's moon Hyperion during a distant encounter in December, 2005. Hyperion is only 280 km (174 miles) across, and is covered with closely packed pits, giving it a spongy appearance. This photo was taken when Cassini was 228,000 kilometers (142,000 miles) from Hyperion.

This is an image of the Claritas Fossae region on the surface of Mars. The photograph was taken by ESA's Mars Express spacecraft, and shows a region approximately 200 km x 1150 km (125 miles by 715 miles). The area is located roughly south-east of the Tharsis volcano group, and shows evidence of ancient tectonic and volcanic activity, as well as many meteor strikes.

In the Northern hemisphere, winter solstice marks the shortest period of daylight during the year. The long nights host an annual parade of familiar constellations and stars, like Orion the hunter, Taurus the bull, brilliant Sirius and ruddy Aldebaran. But to star gazers and astrophotographers alike, the Northern winter also signals the opening of galaxy season; when some of the brightest and most interesting island universes are poised above the horizon for much of the evening.

Paleobiologists have produced 3-D images of ancient fossils - 650 to 850 million years old - embedded within rocks. This astounding accomplishment uses a technique called Raman spectroscopy, which allows scientists to see the structure of these ancient fossils in three-dimensions. This could be useful for future rock samples returned from Mars since would allow scientists to detect and analyze microfossils without actually damaging them.

Astronomers have confirmed that the newly discovered 10th planet is larger than Pluto. Nicknamed 2003 UB313 for now, the new planet has a diameter of 3,000 km (1,850 miles) which is 700 km (435 miles) larger than Pluto. These new observations were made using a sensitive sensor on the IRAM 30-m telescope that measured the heat emitted by the new object, and found it had a similar reflectivity to Pluto. This allowed them to calculate its size.

UC Berkeley researchers have performed a detailed analysis on a binary pair of asteroids circling near Jupiter's orbit, and believe they're mostly water ice covered with a layer of dirt. These objects probably started out as small Kuiper belt objects, and then were captured at one of Jupiter's Trojan points - a gravitational eddy in space where solar system material can collect.

For many years astronomers have known that massive, bright stars are usually found to be in multiple star systems. But a recent study by Charles Lada of the Harvard-Smithsonian Center for Astrophysics suggests that most stars are actually all alone. A new study on low-mass stars - such as red dwarfs - has found that these stars rarely occur in multiples and that they are more abundant than high-mass stars, such as the Sun. Since planets form more easily around single stars, they could be more common than previously thought.

Scientists think they're closing in on the cause of gamma ray bursts: merging neutron stars. It was originally believed that this happened when huge stars in a binary system both turned into neutron stars, and eventually smashed into each other. But astronomers think that neutron stars in globular star clusters could eventually pair up. The stars are packed so closely together, that they often exchange partners; a neutron star could swap a regular star out for another neutron star.

This Cassini photograph highlights tectonic faults and craters on Saturn's moon Dione. This enhanced-colour view was created by merging ultraviolet, green and infrared photographs into a single image which was then superimposed over top of clear-filter image. The photographs were taken on December 24, 2005, when Cassini was 151,000 kilometers (94,000 miles) from Dione.

Having successfully delivered its fragile payload of comet and interstellar dust samples, Stardust is a spaceship without a purpose. This week, NASA controllers sent a series of commands that put the ship into a hibernation mode. With every system turned off, except it solar arrays and receive antenna, Stardust should be able to remain in good health for years. NASA is considering future missions they could give the spacecraft.

When the Apollo astronauts returned to their lunar landers, they all noticed that the moondust - which had clung to their boots and suits - had some interesting properties. For starters, it smelled like spent gunpowder; as if someone had just fired a gun in the lander. Apollo 17's Jack Schmitt came down with a brief case of extraterrestrial hay fever. It could be that the relatively damp interior of the lander causes particles from the solar wind to evaporate into the air.

Greetings fellow SkyWatchers! The week begins as we have a look into the "Fishmouth" - M43. Then it's time to get Sirius as we learn how and when to look for a white dwarf star. As the Moon returns, we'll have a look at its features as well as some bright sky objects. So keep an eye on the sky, because...
Here's what's up!

Young hot blue star - the supermassive black hole has spoken, it's time for you leave the galaxy. When binary stars stray too close to the centre of the Milky Way, they're violently split apart. One star is put into an elliptical orbit around the supermassive black hole, and the other is kicked right out of the galaxy. Dr. Warren Brown from the Harvard-Smithsonian Center for Astrophysics was one of the astronomers who recently turned up two exiled stars.

This false colour image shows subtle variations across the surface of Dione, one of Saturn's moons. Scientists created this view by combining ultraviolet, green and infrared images into a single photograph that highlights the different regional colour differences. The images were taken on December 24, 2005 when Cassini was 597,000 kilometers (371,000 miles) from Dione.

Ask any farmer - if you want to grow prize winning produce you have start with nutrient rich soil. The same holds true if you have your sights on raising suns.

On the 3rd of February the strangest satellite ever constructed will be launched into orbit by astronauts on board the International Space Station (ISS). The satellite, called SuitSat, is an empty old spacesuit. It's equipped with 3 batteries, a radio transmitter and internal sensors to measure temperature and battery power. The satellite will continuously transmit its conditions to Earth while orbiting it. SuitSat will be broadcasting a radio signal that can be easily heard from the ground using an FM radio tuned to 145.990 MHz.

This enhanced colour image of Rhea shows how this Saturnian moon has been pounded by impacts over millions of years. The two large impact basins at the top of Rhea are very old because they're overprinted by many smaller impacts. The ray like structure on the moon's eastern side comes from a relatively recent impact that sprayed material across Rhea's surface. Cassini took this image on December 23, 2005.

Two stars have been spotted streaking out of the Milky Way, never to return. These stars are part of a new class of objects which astronomers have dubbed "exiles". These are stars which were once part of a binary system that strayed too close to the supermassive black hole at the heart of the Milky Way. The pair is torn apart, and the exiled star is fired off on a trajectory that will take it out of our galaxy. These events occur about once every 100,000 years.

Did 2005 feel like a scorcher? Well, you're right. According to NASA researchers, 2005 was the warmest year for planet Earth in more than a century. Scientists have used weather stations on land, ships on the ocean, and satellite measurements from space to keep track of average global temperatures. Over the last 100 years, temperatures have risen on average by 0.8° C or about 1.4° F. And the five warmest years were 2005, then 1998, 2002, 2003 and 2004.