NASA's Phoenix Mars Lander inserted the four needles of its thermal and
conductivity probe into Martian soil during the 98th Martian day, or sol,
of the mission and left it in place until Sol 99 (Sept. 4, 2008).
The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99
after the probe was lifted away from the soil. The imprint left by the
insertion is visible below the probe, and a shadow showing the probe's
four needles is cast on a rock to the left.
The thermal and conductivity probe measures how fast heat and electricity
move from one needle to an adjacent one through the soil or air between
the needles. Conductivity readings can be indicators about water vapor,
water ice and liquid water.
The probe is part of Phoenix's Microscopy, Electrochemistry and
Conductivity suite of instruments.
The Phoenix Mission is led by the University of Arizona, Tucson, on behalf
of NASA. Project management of the mission is by NASA's Jet Propulsion
Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin
Space Systems, Denver.