Success! Phoenix lands safely on Mars

Space scientists are celebrating after their latest Mars probe survived a perilous landing on the Red Planet to begin a mission to seek out clues to life.

Mars in colourNASA’s $460 million Phoenix craft touched down safely at at 7.53 pm PDT (12.53am UK time). It landed 68 degrees north in the martian arctic region, ready to dig deep into the soil to touch the frozen water for the first time ever.

Back at mission control in Pasadena, scientists clapped, cheered and hugged each other. Then they waited for the first pictures of its icy terrain which were not expected to start arriving until at least an hour after landing.

Phoenix, weighing a third of a ton and the size of a pick-up truck, had been cruising right on course to reach a region never visited before, called the Green Valley in Vastitas Borealis.

Frst it dumped the cruise stage that carried it on its 422 million mile voyage since launch in Florida last August. Then, at 12.46am, it dived into the thin martian atmosphere at 12,750mph, its heat shield reaching a fiery 1,450 C. Other American and European probes already orbiting Mars tracked its descent.

Slowing to 1,000mph, the craft jettisoned its heat shield, and opened its parachute and landing legs. Then, just over 1,000 yards up, it fired 12 retro rockets to slow it to less than 6mph for landing seconds later. The probe then stayed quiet for 15 minutes, waiting for dust churned up by the landing to settle before opening its solar panels.

The manouvres were fraught with danger. A previous attempt to land like this failed in 1999 when NASA’s Mars Polar Lander shut down its rockets too soon, believing from the vibrations that it had already landed.

Phoenix became the first spaceprobe to use the social chat network Twitter on the internet. Members of the team posted regular updates of its progress.

In the next few days, Phoenix will dig 20 inches down into the permafrost with a robotic drill to look for water ice beneath the soil. Then it will analyse samples in its own on-board laboratory to find organic chemicals and check whether conditions could ever have supported life.

The probe is not expected to survive more than six months before the martian winter sets in again and freezes the probe’s equipment and solar batteries. But if it does, it will be awoken in the spring.

Photo: One of the first colour pictures from Phoenix of its surroundings.