Phoenix Returns Treasure Trove for Science
NASA's Phoenix Mars Lander performed its first wet chemistry experiment
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," said Phoenix co-investigator Sam Kounaves of Tufts
University, science lead for the wet chemistry investigation.
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," Kouvanes 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 have 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."
Leslie Tamppari, the Phoenix project scientist from JPL, 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 taking first nighttime
Lander cameras confirmed that white chunks exposed during trench digging
were frozen water ice because they sublimated, or vaporized, over a few
days. The 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
"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
Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Sara Hammond 520-626-1974
University of Arizona, Tucson
J.D. Harrington 202 358-5241