Nasa's Phoenix Mars lander has captured the highest-resolution images ever taken of dust and sand on another planet.

Phoenix fails to scoop up sample of Martian soil
The minuscule specks were collected during Phoenix's dramatic touchdown on the Red Planet over a week ago and photographed by one of the lander's powerful onboard microscopes.

The resolution of the images is 10 times that of previous pictures of the surface taken by Nasa's Mars rovers, scientists said.

"We think we indeed have the first pictures showing the diversity of mineralogy on Mars at a scale that is unprecedented in planetary exploration," said Michael Hecht, of the US space agency's Jet Propulsion Laboratory.

Some of the tiny grains, which are not visible to the naked eye, were "like the classic reddish brown Martian particle", said Professor Tom Pike, of Imperial College London, Phoenix's geology team leader, while others were paler and pink and some translucent.

Together the samples represented "a wide variety of particles both in colouration and size and showed "an unprecedented diversity of geology", he added.
Scientists, however, want to do further tests on particles they are certain come from the planet's surface to rule out contamination from the lander before drawing conclusions about the Martian soil.

One of the tiny particles examined was very pale, but Mr Pike said it was almost certainly not a sample of the ice scientists are confident lies beneath the northern arctic plains where the lander touched down.

He said it was more likely a mineral and "could be a salt-like deposit or it could be quartz" as that amount of ice would have "sublimed" and turned into a gas before it could be photographed.

But that did not suggest ice was not present, he added, as ice and mineral deposits were frequently found together.

The 90-day, $420 million mission aims to probe the Martian surface for evidence of water, considered vital for life, and signs of organic compounds that could indicate the planet once had the ability to sustain rudimentary life.

The lander was due to use its robotic arm to ferry the first soil samples to its onboard instruments on Wednesday but the procedure was delayed by a day after a glitch on one of the orbiting spacecraft that transmits commands to Phoenix.

Mission commanders said yesterday the instructions had been successfully re-sent using the other orbiter and the lander was due to deliver its first sample for testing today.

The first results of the laboratory tests are not expected until next week at the earliest.

Over the past decade Nasa has deployed a fleet of orbiters and rovers to search Mars for signs of water and conditions that might have supported life.

Yesterday, Prof Colin Pillinger of the Open University - renowned for leading the team that sent the ill-fated British Beagle 2 probe to the Red Planet - talked about the prospects that alien life could be found, for instance by Nasa's Phoenix Mars mission, at the Cheltenham Science Festival, which is backed by The Daily Telegraph.

The Phoenix mission is looking for water but Prof Pillinger says that it would be hard to extrapolate from its measurements of the presence of organic - carbon based - molecules to provide direct evidence of life.

"I don't think they would be in a position to tell whether it was a biological molecule."

However, he is confident that alien life will be found, not least because of earlier hints: in 1996, there were headlines worldwide when Nasa announced "possible relic biogenic activity" after analysing the Mars meteorite ALH (Allan Hills) 84001, named after the site where it was found in Antarctica.

Prof Pillinger has also studied ALH 84001 but is best known for his work on another Martian meteorite: EETA 79001. In 1989 Prof Pillinger said the latter contained tentative evidence.

"We might have already found life," he says.

However, Prof Pillinger - who is still searching for the smashed remains of Beagle 2 on the Red Planet - adds that extraordinary claims require extraordinary evidence. "I can't prove it without going back to Mars."