[meteorite-list] Phoenix Lander Digs and Analyzes Soil as Darkness Gathers

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 8 Oct 2008 18:36:15 -0700 (PDT)
Message-ID: <200810090136.SAA24971_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2008-188a

Phoenix Lander Digs and Analyzes Soil as Darkness Gathers
Jet Propulsion Laboratory
October 08, 2008

PASADENA, Calif. -- As fall approaches Mars' northern plains, NASA's
Phoenix Lander is busy digging into the Red Planet's soil and scooping
it into its onboard science laboratories for analysis.

Over the past two weeks, Phoenix's nearly 2.4-meter-long (8 feet) arm
moved a rock, nicknamed "Headless," about 0.4 meters (16 inches), and
snapped an image of the rock with its camera. Then, the robotic arm
scraped the soil underneath the rock and delivered a few teaspoonfuls of
soil onto the lander's optical and atomic-force microscopes. These
microscopes are part of Phoenix's Microscopy, Electrochemistry and
Conductivity Analyzer (MECA).

Scientists are conducting preliminary analysis of this soil, nicknamed
"Galloping Hessian." The soil piqued their interest because it may
contain a high concentration of salts, said Diana Blaney, a scientist on
the Phoenix mission with NASA's Jet Propulsion Laboratory, Pasadena, Calif.

As water evaporates in arctic and arid environments on Earth, it leaves
behind salt, which can be found under or around rocks, Blaney said.
"That's why we wanted to look under 'Headless,' to see if there's a
higher concentration of salts there."

More digging is underway. Phoenix scientists want to analyze a hard, icy
layer beneath the Martian soil surface, and excavating to that icy layer
underneath a rock might give scientists clues about processes affecting
the ice.

So the robotic arm has dug into a trench called "La Mancha," in part to
see how deep the Martian ice table is. The Phoenix team also plans to
dig a trench laterally across some of the existing trenches in hopes of
revealing a cross section, or profile, of the soil's icy layer.

"We'd like to see how the ice table varies around the workspace with the
different topography and varying surface characteristics such as
different rocks and soils," said Phoenix co-investigator Mike Mellon of
the University of Colorado, Boulder. "We hope to learn more about how
the ice depth is controlled by physical processes, and by looking at how
the ice depth varies, we can pin down how it got there."

Over the weekend, on the 128th Martian day, or sol, Phoenix engineers
successfully directed the robotic arm to dig in a trench called "Snow
White" in the eastern portion of the lander's digging area. The robotic
arm then delivered the material to an oven screen on Phoenix's Thermal
and Evolved-Gas Analyzer.

The Phoenix team will try to shake the oven screen so the soil can break
into smaller lumps and fall through for analysis.

The Phoenix lander, originally planned for a three-month mission on
Mars, is now in its fifth month. As fall approaches, the lander's
weather instruments detect diffuse clouds above northern Mars, and
temperatures are getting colder as the daylight hours wane.

Consequently, Phoenix faces an increasing drop in solar energy as the
sun falls below the Martian horizon. Mission engineers and scientists
expect this power decline to curtail activities in the coming weeks. As
darkness deepens, Phoenix will primarily become a weather station and
will likely cease all activity by the end of the year.

The Phoenix mission is led by Principal Investigator Peter Smith at the
University of Arizona. Project management is the responsibility of JPL,
with development partnership by Lockheed Martin in Denver. International
contributions come from the Canadian Space Agency; the University of
Neuchatel, Switzerland; the universities of Copenhagen and Aarhus,
Denmark; the Max Planck Institute, Germany; and the Finnish
Meteorological Institute.

More information about Phoenix is at: www.nasa.gov/phoenix
<http://www.nasa.gov/phoenix> .

------------------------------------------------------------------------

Media contacts: Guy Webster 818-364-6278, guy.webster at jpl.nasa.gov
Rhea Borja 818-354-0850, rhea.r.borja at jpl.nasa.gov
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown 202-358-1726, Dwayne.c.brown at nasa.gov
NASA Headquarters, Washington
Received on Wed 08 Oct 2008 09:36:15 PM PDT