[meteorite-list] Phoenix Returns Treasure Trove for Science

[Ron Baalke]

FROM: Lori Stiles (520-360-0574; lstiles at u.arizona.edu)

Phoenix Returns Treasure Trove for Science
University of Arizona
June 26, 2008

NASA's Phoenix Mars Lander performed its first wet chemistry on Martian soil
flawlessly yesterday, returning a wealth of data that for Phoenix scientists
was like winning the lottery.

"We are awash in chemistry data," said Michael Hecht of NASA's Jet Propulsion
Laboratory, lead scientist for the Microscopy, Electrochemistry and
Conductivity Analyzer, or MECA, instrument on Phoenix. "We're trying to
understand what is the chemistry of wet soil on Mars, what's dissolved in it,
how acidic or alkaline it is. With the results we received from Phoenix
yesterday, we could begin to tell what aspects of the soil might support life."

"This is the first wet-chemical analysis ever done on Mars or any planet, other
than Earth," Phoenix co-investigator Sam Kounaves of Tufts University, science
lead for the wet chemistry laboratory investigation, said.

About 80 percent of Phoenix's first, two-day wet chemistry experiment is now
complete. Phoenix has three more wet-chemistry cells for use later in the
mission.

"This soil appears to be a close analog to surface soils found in the upper dry
valleys in Antarctica," Kounaves said. "The alkalinity of the soil at this
location is definitely striking. At this specific location, one inch into the
surface layer, the soil is very basic, with a pH of between eight and nine. We
also found a variety of components of salts that we haven't had time to analyze
and identify yet, but that include magnesium, sodium, potassium and chloride."

"This is more evidence for water because salts are there. We also found a
reasonable number of nutrients, or chemicals needed by life as we know it,"
Kounaves said. "Over time, I've come to the conclusion that the amazing thing
about Mars is not that it's an alien world, but that in many aspects, like
mineralogy, it's very much like Earth."

Another analytical Phoenix instrument, the Thermal and Evolved-Gas Analyzer
(TEGA), has baked its first soil sample to 1,000 degrees Celsius (1,800 degrees
Fahrenheit). Never before has a soil sample from another world been baked to
such high heat.

TEGA scientists have begun analyzing the gases released at a range of
temperatures to identify the chemical make-up of soil and ice. Analysis is a
complicated, weeks-long process.

But "the scientific data coming out of the instrument has been just
spectacular," said Phoenix co-investigator William Boynton of the University of
Arizona, lead TEGA scientist.

"At this point, we can say that the soil has clearly interacted with water in
the past. We don't know whether that interaction occurred in this particular
area in the northern polar region, or whether it might have happened elsewhere
and blown up to this area as dust."

Phoenix project scientist Leslie Tamppari tallied what Phoenix has accomplished
during the first 30 Martian days of its mission, and outlined future plans.

The Stereo Surface Imager has by now completed about 55 percent of its
three-color, 360-degree panorama of the Phoenix landing site, Tamppari said.
Phoenix has analyzed two samples in its optical microscope as well as first
samples in both TEGA and the wet chemistry laboratory. Phoenix has been
collecting information daily on clouds, dust, winds, temperatures and pressures
in the atmosphere, as well as taken first nighttime atmospheric measurements.
Lander cameras confirmed that white chunks exposed during trench digging were
frozen water ice because they sublimated, or vaporized, over a few days.

Phoenix robotic arm dug and sampled, and will continue to dig and sample, at the
'Snow White' trench in the center of a polygon in the polygonal terrain.

"We believe this is the best place for creating a profile of the surface from
the top down to the anticipated icy layer," Tamppari said. "This is the plan we
wanted to do when we proposed the mission many years ago. We wanted a place just
like this where we could sample the soil down to the possible ice layer."

The Phoenix mission is led by Peter Smith of The University of Arizona with
project management at JPL and development partnership at Lockheed Martin,
located in 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 information on the Phoenix mission, link to
http://www.nasa.gov/phoenix and http://phoenix.lpl.arizona.edu.

MEDIA CONTACTS:
Guy Webster, Jet Propulsion Laboratory
(818-354-6278; guy.webster at jpl.nasa.gov)
J.D. Harrington, NASA HQ
(202-358-5241; j.d.harrington at nasa.gov)
Sara Hammond, University of Arizona
(520-626-1974; shammond at lpl.arizona.edu)