[meteorite-list] NASA's Phoenix Mars Lander Inspects Delivered Soil Samples

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.cfm?release=2008-109

NASA's Phoenix Mars Lander Inspects Delivered Soil Samples
Jet Propulsion Laboratory
June 13, 2008

TUCSON, Ariz. -- 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.

"We've seen no major dust clouds at the landing site during the mission
so far," Renno said. "That's not a surprise because we landed when dust
activity is at a minimum. But we expect to see big dust storms at the
end of the mission. Some of us will be very excited to see some of those
dust storms reach the lander."

Studying dust on Mars helps scientists understand atmospheric dust on
Earth, which is important because dust is a significant factor in global
climate change.

"We've learned there is well-mixed dust in the Martian atmosphere, much
more mixed than on Earth, and that's a surprise," Renno said. Rather
than particles settling into dust layers, strong turbulence mixes them
uniformly from the surface to a few kilometers above the surface.

Scientists spoke at a news briefing today at the University of Arizona,
where new color views of the spacecraft's surroundings were shown.

"We are taking a high-quality, 360-degree look at all of Mars that we
can see from our landing site in color and stereo," said Mark
Lemmon, Surface Stereo Imager lead from Texas A&M University, College
Station.

"These images are important to provide the context of where the lander
is on the surface. The panorama also allows us to look beyond our
workspace to see how the polygon structures connect with the rest of the
area. We can identify interesting things beyond our reach and then use
the camera's filters to investigate their properties from afar."

The Phoenix mission is led by Smith at the University of Arizona with
project management at JPL and development partnership at Lockheed
Martin, Denver. International contributions come from the Canadian Space
Agency; the University of Neuchatel, Switzerland; the universities of
Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the
Finnish Meteorological Institute. For more about Phoenix, visit: 
http://www.nasa.gov/phoenix  and http://phoenix.lpl.arizona.edu.

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Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown at nasa.gov

Sara Hammond 520-626-1974
University of Arizona, Tucson
shammond at lpl.arizona.edu

2008-109