Scientists have confirmed that the Opportunity Mars
rover has run across a meteorite, sitting within the robot's exploration zone at
Meridiani Planum.
"We have definitive word now... it's a meteorite,"
Steve Squyres, principal science investigator for the Mars Exploration Rover
program told SPACE.com. Squyres is based at Cornell University in
Ithaca, New York.
Opportunity has been using both cameras and science
gear to study the intriguing pitted rock on Mars, now dubbed "Heat Shield
Rock".
Wheeling about the open landscape of Meridiani
Planum, Opportunity had been busily inspecting heat-shield wreckage -- hardware
leftovers from the spacecraft's plummet to Mars in January of last
year.
Completing one of several debris surveys, the robot
then turned and drove north toward Heat Shield Rock. The rover traversed about
33 feet (10 meters), parking itself at the desired standoff distance of about
3.3 feet (one meter) to acquire remote sensing of the rock.
Opportunity then acquired additional remote sensing,
bumped forward closer to the rock, putting the odd object within the work volume
of the tools mounted at the tip of the robot's mechanical arm.
Tempting target
Initial looks at the rock stirred considerable
speculation that the object could be a meteorite - speculation now confirmed.
Opportunity's Mini-Thermal Emission Spectrometer (Mini-TES) was suggestive that
the find was metal in nature.
Last week, Squyres took a wait-and-see mode, eagerly
awaiting tell-tale data recorded by Opportunity to be transmitted to Earth last
weekend. The rover's Mössbauer Spectrometer was moved into position over the
suspect meteorite, to determine the composition and abundance of iron-bearing
minerals.
Earlier last week, Laurie Leshin, Director of the
Center for Meteorite Studies at Arizona State University in Tempe, Arizona was
tempted by the images to conclude that the object was, indeed, a
meteorite.
"Not sure if it is or not, but it does sorta look
like one," Leshin told SPACE.com. "Looks a lot like an iron [meteorite]
to me."
Given the robot's suite of science instruments,
Leshin said the rover should be able to identify whether or not the rock was a
meteorite.
Questions to ponder
The fact that Opportunity might have come across a
meteorite raises a number of issues, Leshin hypothesized before the confirmation
by Squyres and his science team.
"To me it is interesting for several speculative
reasons," Leshin said. First of all, depending on the size, it may indicate that
it fell during the time of a thicker atmosphere, she said.
"But we haven't done the calculation yet. Things much
bigger than it appears to be wouldn't be slowed down by today's thin atmosphere
[on Mars], and thus they would make a crater rather than a 'soft landing'",
Leshin explained.
Leshin also conjectured about the shiny nature of the
object. "Is it because...meteorites don't react with the atmosphere as on Earth or
has it been sandblasted?" Lastly, iron metal is one of the most susceptible
things to weathering/rust in the presence of water.
"Thus, a
nicely preserved meteorite -- unless we're unlucky and it fell yesterday, which
we would never know -- strongly supports the idea that current weathering rates
[on Mars] are incredibly low," she said.
advertisement
