[meteorite-list] Opportunity Rover Finds Yet Another Meteorite on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 12 Oct 2009 09:10:55 -0700 (PDT)
Message-ID: <200910121610.n9CGAtX1016803_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n0910/11meteorite/

Opportunity rover finds yet another Mars meteorite
BY CRAIG COVAULT
SPACEFLIGHT NOW
October 11, 2009

In a remarkable discovery 126 million miles from Earth, the Mars rover
Opportunity has found a second large iron meteorite sitting just a half
mile from its twin sibling where they both landed on Mars within seconds
of each other 3 billion years ago.

The new "Sheltered Rock" meteorite discovered by Opportunity Oct. 2,
lies only 2,300 feet away from the "Block Island" meteorite that the
rover discovered in July and examined for six weeks.

Designated "Sheltered Rock" by the rover team, the new meteorite almost
certainly came from the same body as Block Island that was discovered
July 18. They both laid undisturbed at the same spot until Opportunity
stumbled across them while driving west across the Meridiani plain.

Sheltered Rock is about 18.5 inches long compared with about two feet
for Block Island. Each weighs several hundred pounds and are quite
similar to each other.

Analysis indicates both fell about 3 billion years ago when Mars had a
much thicker atmosphere that slowed impact velocity so the rocks did not
explode and dig craters when they hit the planet.

An inspection plan is being drawn up at Cornell University and Jet
Propulsion Laboratory to use the rover's robotic arm to place its
spectrometers and microscopic imager on Sheltered Rock for a direct
comparison with data from Block Island.

Discovery of the second body will also provide new data on both the
meteorite and early Martian atmosphere since it is likely whatever
aerodynamic forces it did encounter, resulted in separation of the pair
at a low enough altitude for both of them to hit so close together.

It is not unusual on Earth to find multiple pieces from the same
meteorite event. But on Mars with a single rover, driving in a specific
direction, it is remarkable that Opportunity encountered a second
meteorite related to the first.

The new discovery is also the third meteorite found by Opportunity since
it discovered a much smaller basketball sized meteorite lying near its
heat shield ten months after landing in January, 2004.

In addition to being smaller, that initial meteorite dubbed Heat Shield
Rock looks more rounded and polished than the more rectangular Block
Island and Sheltered Rocks. Data from all three will be compared to see
if Heat Shield rock could also be related to the original body that
spawned the more recent finds. All three fell relatively close together
with Heat Shield rock only about 11 miles away from the other two.

Opportunity had been driving west for three weeks after it left Block
Island to continue its journey toward Endeavour crater, still more than
a years drive time away to the south. The jog west was to avoid
dangerous terrain. Images taken on about sol (Martian day) 2,020 of its
mission spotted something unusual ahead. On sol 2,022 Opportunity
completed a drive of 94 feet to pull up beside what turned out to be the
Sheltered Rock meteorite.

While Opportunity continues to score scientifically on its marathon
traverse to Endeavour crater, the rover Spirit on the opposite side of
Mars remain stuck in powdery volcanic material where it was halted in
early May. JPL computer runs using physical data from two test rovers in
a JPL sand box continue to asses escape techniques. But it looks
increasingly likely that Spirit's driving days are over although it's
Cornell University Athena science package will continue to return
valuable data even if it is stuck for good.

Steve Squyres rover principal investigator at Cornell has also just won
a prestigious award for communicating the rover story to the public.

For his work making NASA's Mars Exploration Rover mission a compelling
saga for millions of people, Steven W. Squyres has received the 2009
Carl Sagan Medal from the American Astronomical Society.

The Sagan medal recognizes a planetary scientist for excellence in
public communication. Squyres received the medal during the AAS's
Division for Planetary Sciences annual meeting, Oct. 4 to Oct. 9, in
Puerto Rico.

In addition to heading rover science operations Squyres is also the
Goldwin Smith Professor of Astronomy at Cornell where he was quick to
share credit with the entire Mars rover mission team there and at JPL.
Squyres said he has always taken seriously the responsibility of giving
people -- the taxpayers who have bankrolled the mission -- a clear
window into what they are doing on Mars.

"We feel very strongly that the people who pay have a real right to find
out in very clear, simple terms what they're getting for their $900
million," Squyres said.

Since January, 2004, when Spirit and Opportunity landed, the rover team
has maintained a publicly accessible database of images taken by the
spacecraft. Atypical of most NASA missions, the rover project has
allowed people to access data almost immediately. It was a conscious
decision by the rover team, Squyres said, to pipeline the data straight
to the Web. Squyres told Spaceflight Now that some senior NASA managers
were against this approach early on.

"If I'm asleep and you're awake, you can see the pictures from the rover
before I do," Squyres said. "And what that has done is it's really
enabled people to share in this voyage of exploration."

Squyres hopes these efforts, including the Web site that provides
updates of rover activities, has inspired young people to pursue careers
in science and engineering.

As a Cornell graduate student in the early 1980s Squyres began working
closely with Sagan who died in 1996. "Carl really pioneered, in a very
important way, the way in which scientists interact with the media and
the public," Squyres said. "To receive an award that's named after him
for trying to do the same sort of thing that he did so brilliantly is a
real honor."
Received on Mon 12 Oct 2009 12:10:55 PM PDT