THE European Space Agency鈥檚 Mars Express orbiter has released its first image of the Red Planet: a landscape gashed with valleys in a section of the solar system鈥檚 grandest canyon, Valles Marineris.
Taken from 275 kilometres above the surface, the colour portrait shows details as small as 12 metres across in a patch of land 65 kilometres across. The island-shaped mesas, mountain ridges, and valleys in what is now dry terrain just south of the Martian equator were probably carved by ancient glaciers, says Agustin Chicarro, Mars Express project scientist. Streaks of white along the sides of ridges and mesas may be morning mist or recently exposed rocks that have slipped down the kilometre-high slopes.
The High Resolution Stereo Camera responsible for the image has even better surprises in store, say project scientists. The camera will snap the entire planet in 3D at a resolution of 100 metres and selected regions at 2 metres. 鈥淲e will have views like Spirit鈥檚, but everywhere over Mars,鈥� says Jan-Peter Muller, an astronomer at University College London.
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Anticipation is also rising for Spirit鈥檚 identical twin, Opportunity, which will land on the planet this weekend. All the pictures taken so far by landers on the surface of Mars look similar: rust-coloured landscapes with dark boulders, pebbles and distant hills.
But Opportunity鈥檚 target site, Meridiani Planum, 鈥渨ill look completely different鈥�, says project scientist Matt Golombek. It should have almost none of the reddish, iron-rich dust that has dominated the sites visited so far. Instead, there should be a large amount of haematite 鈥� a dark grey iron oxide usually formed in bodies of water. Meridiani is also one of the flattest sites on the whole planet. In fact, the lack of landmarks may make it tough to work out exactly where the rover has landed.
The landing is set for Sunday morning, at 0505 GMT. Even though Spirit鈥檚 touchdown worked perfectly, the team is being cautious about Opportunity. 鈥淚 don鈥檛 know that I鈥檓 any more confident of the second one landing than I was of the first,鈥� says Maria Zuber, a planetary scientist who helped plan the landing. She says there are still many unknowns about the temperature profile of the atmosphere at Meridiani Planum, which will crucially affect parachute deployment. This will also be the highest-altitude landing ever attempted on Mars, close to the upper limit for a safe touchdown.