Some of the first images sent back to Earth by NASA's Opportunity rover are of exposed layered rock which could have been formed gradually by water - where there's water, there could have been life. Astrobiologist Andrew Knoll is a science team member with the rover missions, and a Fisher Professor of Natural History at Harvard University. He explains how scientists search for extreme life on Earth, and how discoveries here could help the rovers spot evidence of past life on Mars.

NASA's Opportunity rover took a close look at the Martian soil near its landing site yesterday with its microscope, and controllers released the first colour images today. What's unusual about the soil is just how many spherical-shaped particles there are. There are only a few processes which can create this shape of particles, such as the gentle rolling at the bottom of an ocean. It's possible for a volcano or asteroid impact to create spherical particles; globs of lava can freeze in mid-air as they're ejected. The largest pebble in this image is approximately 3 mm across.

A team of astronomers have discovered what seem to be clouds of hydrogen gas which were left over when the Andromeda galaxy formed. The clouds were discovered using the Robert C. Byrd Green Bank Telescope (GBT), which is the world's largest fully steerable radio telescope. Galaxies like Andromeda, and our own Milky Way, were thought to have formed by the continuous merging of smaller galaxies as well as the accretion of clouds of hydrogen. Astronomers had been unable to find these clouds until now.

Using satellite data, scientists think they might have a way to give some advance warning of landslides, which kill hundreds of people around the world every year. Scientists know that regions which are about to turn into a landslide can shift slightly. Local observers would never notice a few millimeters of movement, but it's possible for satellites to track it from space using a technique called radar interferometry. Analysts compare multiple images of the same location which allows them to highlight regions which have shifted slightly.

NASA Administrator Sean O'Keefe announced on Monday that seven hills to the east of the Spirit rover's landing site would be named for the astronauts who lost their lives when the space shuttle Columbia was destroyed. The hills are between 3 and 5 kilometres away from Spirit's landing spot, and NASA will submit them to the International Astronomical Union for official designation.

At the end of February 2004, the European Space Agency's Rosetta spacecraft is expected to launch on board an Ariane 5 launcher from the space centre in Kourou, French Guiana. Rosetta will travel 675 million kilometres, including multiple planet flybys to reach Comet Churyumov-Gerasimenko in 2014 - it will orbit the comet and then actually land on its surface. This journey will be a long time coming, since Rosetta has been in development since 1997, and missed several launch opportunities.

Both of NASA's twin rovers are now ready to perform a scientific study of Mars with the suite of tools at the end of their robotic arms. Opportunity extended its arm for the first time today, while Spirit has been locked with its arm stretched out for the last few weeks. Controllers will have Opportunity examine a patch of soil right in front with its microscope and Moessbauer Spectrometer, and then it will turn the arm and look at another patch with its alpha particle X-ray spectrometer. This should tell scientists back at Earth what minerals are in the soil.

After 10 days of recovery work, engineers at NASA have given Spirit a clean bill of health; the rover is now booting up normally. The recovery happened after controllers deleted thousands of files loaded up in the rover's memory; most of which was stored up from the seven-month flight from the Earth to Mars. The engineers are still planning to completely wipe the memory to start with a clean slate, and then reinstall all the software. Spirit will continue examining a rock called Adirondack later this week with its suite of scientific tools.

An unmanned Russian Progress cargo ship docked with the International Space Station on Saturday, delivering over two tones of food, water, fuel, supplies and scientific equipment. Progress 13 automatically docked to the Zvezda Service Module at 1313 UTC (8:13am EST) Saturday afternoon. This is the first spacecraft to visit the station since astronaut Michael Foale and cosmonaut Alexander Kaleri were launched more than 100 days ago.

Astronomers made news in early 2003 with a precise measurement for the age of the Universe - 13.7 billion years - using data from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) satellite. But new research from the University of Durham indicates that our view into the past might be skewed by clusters of galaxies which seem to be in regions where the microwave energy is lower. It's possible that hot gas in the galaxy clusters is interfering with photons from the Big Bang, and has corrupted the microwave map of the sky. These results may undermine theories about how the early Universe was dominated by dark matter and dark energy.

Michael Benson, author of Beyond: Visions of the Interplanetary Probes (read Universe Today's review) took some time from his busy schedule, and nasty cold, to answer some of our questions about his book and interest in astronomy and space exploration. Benson was interviewed by Mark Mortimer.

New data gathered by the Hubble Space Telescope shows that a previously discovered extrasolar gas giant which has oxygen and carbon in its atmosphere evaporating at a tremendous rate. The planet - officially called HD 209458; unofficially "Osiris" - orbits its star at only 7 million km and has created an extended ellipse of material around the star. This discovery has caused astronomers to propose a new kind of object called a cthonian: the dead cores of gas giants which have been stripped of their atmosphere.

Filmmaker James Cameron (Titanic, Aliens) is an advocate for human missions to Mars, and feels that quality images will go a long way to help boost the public's enthusiasm for space. While working on a book, miniseries and possible 3-D movie, Cameron did a tremendous amount of research looking through NASA material, and produced a series of images that might help showcase what the key phases and hardware of a human mission to Mars might look like.

NASA's Opportunity rover successfully rolled off its lander today and out onto the Martian surface - both rovers are now firmly on Martian soil. The commands to drive were given Saturday morning, and cheers erupted at JPL when the first images came back showing tracks in the dust back to the lander. "We're two for two! One dozen wheels on the soil." JPL's Chris Lewicki, flight director, announced to the control room. The flight team ended up only requiring seven days to get Opportunity off the lander, compared to twelve days for Spirit.

New data gathered by the Chandra X-Ray Observatory shows how stars can be more durable than previously thought. Astronomers measured the light from an object called V471, which is believed to be a white dwarf and Sun-like star orbiting one another very tightly. The white dwarf used to be a red giant star many times larger than our own Sun which blew up so large the Sun-like star was completely engulfed, but it actually survived the ordeal; it bears the unique signature of material that it accreted while it was inside the giant's envelope.

NASA's Spirit rover has gotten back to work sending pictures back to Earth, now that engineers have worked through most of the problems that plagued the rover over the last week. Spirit took a picture of its robotic arm, extended out towards a rock, to show that it was still in the same position when the glitches occurred. On the other side of the planet, Opportunity's landing platform was tilted forward to prepare for the rover's exit on Sunday or Monday.

People usually associate squads of bespectacled engineers and scientists as being the sole guardians of space. Beyond: Visions of the Interplanetary Probes by Michael Benson is the type of book that rationalizes and moreover encourages the inclusion of other specialists, especially those in the arts. Containing 295 photographs chosen both for their artistic, awe inspiring impact as well as their voluminous scientific content, the reader will want to quickly put aside numerical calculations about orbital mechanics and let their eyes float across the vistas of other planets.

Dr. Nathalie Cabrol, a planetary geologist with the SETI Institute and NASA's Ames Research Center, has been working for more than a decade to explore the mysteries of Gusev Crater - the spot where the Spirit rover landed earlier this month. Dr. Cabrol, and her husband Dr. Edmond Grin initially proposed the landing spot to NASA because the area seems to once have held an ancient lakebed.