NASA's
Phoenix Mars Lander has successfully stretched out its robotic arm to scratch
at the Martian soil for the first time, mission scientists said Monday.
Phoenix
performed the test dig Sunday in a spot just above a dent left by the scoop of
its robotic arm when it first touched the soil on May 31. Researchers dubbed
the dent "Yeti" because of its strong resemblance to a
footprint.
Touching
the soil and performing this so-called "dig and dump" are the first
practice steps toward digging up soil samples and delivering them to the
instruments on the lander. The instruments aboard the
$420-million spacecraft are designed to analyze the soil and underlying
layers of water ice to see if the ice was at some point liquid and whether it
could have created a habitable zone for microbial life.
Phoenix not only scooped up and dumped
material on the Martian surface, it also snapped a photo of the stuff in its
back hoe-like maw.
"The
soil is crumbly and there's also some light-toned bits," said Ray
Arvidson, the robotic arm co-investigator of Washington University in St. Louis.
These
"light-toned bits" were also seen in the trench left by the scoop.
"We got very excited because we see this nice streak of white
material," said Phoenix senior engineer Pat Woida.
What
exactly the white material is is uncertain, though Arvidson proposed one of two
possibilities.
First, the
white material could be salts that formed while liquid water was present.
Second, and more tantalizing, the stuff could also be part of the underlying
ice layer similar to the smooth
bright regions spotted under the lander in photographs, which mission
scientists also think could be ice
exposed by the thrusters as the craft landed. Researchers christened the
odd regions "Snow Queen" and "Holy Cow."
"We
were so excited about it we called it Holy Cow," Arvidson said.
The success
of Sunday's practice dig and dump means that the team can focus on the next
stage of Phoenix's mission: sampling and analyzing the soil.
"That
was all very, very successful, so I don't think we need to do any more
testing," Arvidson said.
The team is
currently scouting for new dig sites, which will likely be three side-by-side
areas (one for each of the lander's three analysis instruments), which the team
plans to name "Baby Bear," "Mama Bear" and "Papa
Bear." The dig targets will likely be just to the right of the test dig,
where Phoenix's 7.7-foot (2.3-meter) robotic arm can easily reach.
The team
has gone back to their original plan of delivering the first sample to the
lander's Thermal and Evolved-Gas Analyzer (TEGA), which heats up samples and
analyzes the vapors they give off, after a glitch over the weekend has been
worked out. A filament in part of the analyzer shorted out, but mission
engineers have found that they can use a second, back-up filament to do the
analysis with the same amount of sensitivity.
Mission
controllers will look at the data from Phoenix's downlink on Monday night and
if the TEGA covers have fully retracted, "then TEGA will be good to
go," Arvidson said.
NASA's Phoenix Mars Lander touched
down in the Martian arctic on May 25 to begin a planned three-month mission
studying the surrounding terrain, weather and searching for water ice.
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