A NASA
probe circling Mars is back at full strength as researchers ponder its past views
of possible cave entrances on the red planet's surface.
The agency's
Mars Odyssey spacecraft resumed science operations this week after spending several
days in 'safe mode' due to a Sept. 14 software glitch. While in safe mode, a
precautionary configuration designed to preserve the orbiter's health during a
glitch, engineers on Earth methodically restored Odyssey's onboard systems.
"The
spacecraft reacted exactly as it was designed to for this condition," said
Robert Mase, NASA's Odyssey mission manager at the Jet Propulsion Laboratory in
Pasadena, Calif., earlier this week.
Meanwhile,
researchers are hoping to use the revived probe and other red planet orbiters
to hunt for more cave-like pits akin to those found by Odyssey and the Mars
Global Surveyor earlier
this year. Dubbed the "Seven Sisters," the dark holes were discovered on a
massive martian volcano dubbed Arsia Mons and range between 328 to 820 feet (100
to 250 meters) in diameter, mission managers said.
"They
are cooler than the surrounding surface in the day and warmer at night," said
Glen Cushing of U.S. Geological Survey's Astrogeology Team and Northern Arizona University in Flagstaff, Ariz., in a Friday statement. "Their thermal
behavior is not as steady as large caves on Earth that often maintain a fairly
constant temperature, but it is consistent with these being deep holes in the
ground."
Researchers
described Odyssey's potential cave finds, which were previously
reported on SPACE.com, in a recent online edition of the journal Geophysical
Research Letters.
"Whether
these are just deep vertical shafts or openings into spacious caverns, they are
entries to the subsurface of Mars," said study co-author Tim Titus, of the
U.S. Geological Survey, in a statement. "Somewhere on Mars, caves might
provide a protected niche for past or current life, or shelter for humans in
the future."
Because the
martian Seven Sisters are perched high up on Arsia Mons, near Mars' tallest
mountain, their extreme altitude would make their location a poor candidate to
support future astronaut bases or possible microbial life, mission researchers
said.
With Mars
Odyssey now out of safe mode, the orbiter can also resume its role as a
communications relay between NASA's twin red planet rovers Spirit and Opportunity on the
martian surface.
While
Odyssey was unavailable, the rovers beamed their daily communication signals
directly to Earth, NASA officials said. The orbiter launched towards Mars in
2001 and is partway through its second mission extension, they added.
Another
planetary probe jointly run by NASA, the international Cassini spacecraft currently
orbiting Saturn, is also back to work after its own safe
mode session.
A power
trip caused by a run-in with a cosmic ray put Cassini in safe mode on Sept. 11
after the probe's flyby
past Saturn's moon Iapetus. The glitch delayed the spacecraft's
transmission of the flyby data by about a day and the probe was back to full
operation by Sunday, NASA officials said.
advertisement
