Bright Chunks at Phoenix Lander's Mars Site Must Have Been Ice

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

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

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

NEWS RELEASE: 2008-113 June 19, 2008

Bright Chunks at Phoenix Lander's Mars Site Must Have Been Ice

TUCSON, Ariz. -- Dice-size crumbs of bright material have vanished from inside a
trench where they were photographed by NASA's Phoenix Mars Lander four days ago,
convincing scientists that the material was frozen water that vaporized after digging
exposed it.

"It must be ice," said Phoenix Principal Investigator Peter Smith of the University of
Arizona, Tucson. "These little clumps completely disappearing over the course of a few
days, that is perfect evidence that it's ice. There had been some question whether the
bright material was salt. Salt can't do that."

The chunks were left at the bottom of a trench informally called "Dodo-Goldilocks" when
Phoenix's Robotic Arm enlarged that trench on June 15, during the 20th Martian day, or
sol, since landing. Several were gone when Phoenix looked at the trench early today, on
Sol 24.

Also early today, digging in a different trench, the Robotic Arm connected with a hard
surface that has scientists excited about the prospect of next uncovering an icy layer.

The Phoenix science team spent Thursday analyzing new images and data successfully
returned from the lander earlier in the day.

Studying the initial findings from the new "Snow White 2" trench, located to the right of
"Snow White 1," Ray Arvidson of Washington University in St. Louis, co-investigator
for the robotic arm, said, "We have dug a trench and uncovered a hard layer at the same
depth as the ice layer in our other trench."

On Sol 24, Phoenix extended the first trench in the middle of a polygon at the
"Wonderland" site. While digging, the Robotic Arm came upon a firm layer, and after
three attempts to dig further, the arm went into a holding position. Such an action is
expected when the Robotic Arm comes upon a hard surface.

Meanwhile, the spacecraft team at Lockheed Martin Space Systems in Denver is
preparing a software patch to send to Phoenix in a few days so scientific data can again
be saved onboard overnight when needed. Because of a large amount a duplicative file-
maintenance data generated by the spacecraft Tuesday, the team is taking the precaution
of not storing science data in Phoenix's flash memory, and instead downlinking it at the
end of every day, until the conditions that produced those duplicative data files are
corrected.

"We now understand what happened, and we can fix it with a software patch," said
Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory,
Pasadena. "Our three-month schedule has 30 days of margin for contingencies like this,
and we have used only one contingency day out of 24 sols. The mission is well ahead of
schedule. We are making excellent progress toward full mission success."

The Phoenix mission is led by 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. The latest Phoenix
images and information are at http://www.nasa.gov/phoenix and

http://phoenix.lpl.arizona.edu.

-end-

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=dnJMKPNpEfKLK0L&s=lvL4JaMRKhKQI9MXKvH&m=cqLILXOzFcJXF