Minor Glitch Detected In Thermal and Evolved Gas Analyzer
Scientists have discovered what may be ice that was exposed when
soil was blown away as NASA's Phoenix spacecraft landed on Mars
last Sunday. The possible ice appears in an image the robotic arm
camera took underneath the lander, near a footpad.
"We could very well be seeing rock, or we could be seeing
exposed ice in the retrorocket blast zone," said Ray Arvidson of
Washington University, St. Louis, MO co-investigator for the
robotic arm. "We'll test the two ideas by getting more data,
including color data, from the robotic arm camera. We think that if
the hard features are ice, they will become brighter because
atmospheric water vapor will collect as new frost on the ice.
"Full confirmation of what we're seeing will come when we
excavate and analyze layers in the nearby workspace," Arvidson
Testing Thursday night of a Phoenix instrument that bakes and
sniffs samples to identify ingredients identified a possible short
circuit. This prompted commands for diagnostic steps to be
developed and sent to the lander in the next few days. The
instrument is the Thermal and Evolved Gas Analyzer. It includes a
calorimeter that tracks how much heat is needed to melt or vaporize
substances in a sample, plus a mass spectrometer to examine vapors
driven off by the heat. The Thursday, May 29, tests recorded
electrical behavior consistent with an intermittent short circuit
in the spectrometer portion.
"We have developed a strategy to gain a better understanding of
this behavior, and we have identified workarounds for some of the
possibilities," said William Boynton of the University of Arizona,
Tucson, lead scientist for the instrument.
The latest data from the Canadian Space Agency's weather station
shows another sunny day at the Phoenix landing site with
temperatures holding at minus 30 degrees Celsius (minus 22 degrees
Fahrenheit) as the sol's high, and a low of minus 80 degrees
Celsius (minus 112 degrees Fahrenheit). The lidar instrument was
activated for a 15-minute period just before noon local Mars time,
and showed increasing dust in the atmosphere.
"This is the first time lidar technology has been used on the
surface of another planet," said the meteorological station's chief
engineer, Mike Daly, from MDA in Brampton, Canada. "The team is
elated that we are getting such interesting data about the dust
dynamics in the atmosphere."
The mission passed a "safe to proceed" review on Thursday
evening, meeting criteria to proceed with evaluating and using the