Particles of Soil on Silicone - Sol 17 (1 - credits: NASA/Univ. of Arizona)

New observations from NASA's Phoenix Mars Lander provide the most magnified view ever seen of Martian Soil, showing particles clumping together even at the smallest visible scale.

In the past two days, two instruments on the lander deck -- a microscope and a bake-and-sniff analyzer -- have begun inspecting soil samples delivered by the scoop on Phoenix's Robotic Arm.

"This is the first time since the Viking missions three decades ago that a sample is being studied inside an instrument on Mars," said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson.

Stickiness of the soil at the Phoenix site has presented challenges for delivering samples, but also presents scientific opportunities. "Understanding the soil is a major goal of this mission and the soil is a bit different than we expected," Smith said. "There could be real discoveries to come as we analyze this soil with our various instruments. We have just the right instruments for the job".

Images from Phoenix's Optical Microscope show nearly 1,000 separate soil particles, down to sizes smaller than one-tenth the diameter of a human hair. At least four distinct minerals are seen.

"It's been more than 11 years since we had the idea to send a microscope to Mars and I'm absolutely gobsmacked that we're now looking at the soil of Mars at a resolution that has never been seen before," said Tom Pike of Imperial College London. He is a Phoenix co-investigator working on the lander's Microscopy, Electrochemistry and Conductivity Analyzer.

The sample includes some larger, black, glassy particles as well as smaller reddish ones. "We may be looking at a history of the soil," said Pike. "It appears that original particles of Volcanic Glass have weathered down to smaller particles with higher concentration of Iron".

The fine particles in the soil sample closely resemble particles of airborne dust examined earlier by the microscope.

Atmospheric dust at the Phoenix site has remained about the same day-to-day so far, said Phoenix co-investigator and atmospheric scientist Nilton Renno of the University of Michigan, Ann Arbor.