Posted on 08/09/2005 1:18:11 PM PDT by LibWhacker
NASA's twin Mars rovers continue to turn up intriguing new rock formations after a combined total of nearly 1120 Martian days on the planet.
After discovering relatively little, other than basaltic lava flows, during its first six months on the Red Planet, Spirit continues to make up for lost time as it ascends Husband Hill - unearthing clues to violence in the planet's youth.
Meanwhile, Opportunity is also experiencing a reversal of fortune on the other side of Mars. After trudging over desolate stretches of sand for about five months, it has finally reached an island of bedrock that appears unlike anything yet seen in the mission.
Spirit landed in the lava plains of Gusev Crater, getting off to a slow start in its mission. But since it began clambering up to higher ground in the Columbia Hills in July 2004, it has seen granular rocks with a mix of grain sizes. And recently it has seen the most extreme case of this from a spot about 20 metres below the summit of Husband Hill, which rises about 80 metres above the floor of Gusev Crater.
Plum pudding
About a week ago, Spirit paused to study an outcrop called Voltaire. The outcrop is made of large, often angular "pebbles" that appear to have a different composition than the finer-grained material in which they are embedded.
The rovers' chief scientist, Steve Squyres at Cornell University in Ithaca, New York, US, says the "plum pudding" composition hints at an explosive event such as a volcanic eruption or impact.
That view is strengthened by another rock that Spirit has been scrutinising for the last few days. Called Assemblee, it appears to be made of "cruddy glass" that may have been melted by such an event.
"The diversity of rock types is staggering," Squyres told New Scientist. He believes impacts may be to blame, pointing out that Spirit has previously uncovered rocks with high concentrations of nickel - an element found in many meteorites. The impacts would blast away different layers of the surface and jumble them together as they crashed down again. "You're basically throwing it into a blender," he says.
Early influences
But colleague Ray Arvidson of Washington University in St. Louis, Missouri, US, says there may be more to the story. "I think the crust is too complicated to have been produced by one process or one event," he says, adding that volcanic eruptions, impacts, wind and water all may have played a role. "These granular rocks were broken up, transported, put in place and cemented."
He says the Columbia Hills are even older than the approximately 3 billion-year-old volcanic plains that make up Gusev's floor and therefore contain clues about the events that shaped early Mars.
As Spirit continues towards the summit of Husband Hill and then proceeds down its southern slope, team members will compare the rocks to others they have studied. "If we see an even greater variety of rocks than we’ve observed so far, it will argue against one or two big events," Arvidson says.
Out to sea
On the other side of the planet, Opportunity is beginning to do some serious science of its own after a long stint of somewhat fruitless roaming. "Opportunity was the glamour rover for the first six months of the mission, but for the last five months, it has been trudging across a bleak plain of sand," says Squyres. "We felt like sailors who have been out to sea for months."
But within the last couple of days, the rover finally reached a little spot of bedrock - one of several scattered around the area. And it may prove worth the wait.
The rover used its rock abrasion tool to scrape the rock and found "blueberries” - broadly similar to those found in other places on Mars - that appear to have formed in the presence of water. But these have different size distributions and are not as spherical as those seen previously, suggesting the composition of the rock is different, says Squyres.
After studying this outcrop further, the team may send Opportunity farther south on Wednesday, towards an old, shallow crater called Erebus.
On Wednesday, NASA's Mars Reconnaissance Orbiter is also set to blast off to Mars. It will begin its work in November 2006, scanning the surface from a relatively low altitude of about 305 kilometres.
Shouldnt that be "Unmarsing clues"
Out here on the west coast JPL opens their doors for an entire weekend and shows you the works. Kids get run over by a rover (lie down and the rover literally runs over them), get to see moon rocks, try on a astronaut suit, etc. It's fabulous and very well attended.
I really didn't know. No harm was intended.
Actually the European Space Agency's orbiter that carried the failed lander is working great.
The Lander that crashed was a British project done on a shoestring budget.
Pure dumb luck???----Not!
"We've certainly gotten our moneys worth out of those two."
Yeah, now we know there are rocks on Mars.
You have to be really incompetent to get it right twice and simultaneously to boot!
Good news story that needs more press than it is getting.
Correct. This is an amazing success story and there is very little coverage by the major media. I don't know how much NASA is trying to get this story out, but they need to try harder.
> There is no future in space and they know it.
There is no future *without* space and you know it.
I love the 21st Century! Now if we could only re-program all these moon worshipping demons who seem to have come straight out of the Dark Ages, mankind would have it made.
The pictures on the website are breathtaking. And just scroll down to the picture posted by cripplecreek.
Thanks for that info. Wish I could take a tour myself.
Any pictures of where the astronauts planted the American flag?
Oh, please! That can't be real.
LOL Thank you congresswoman.
No future in space? Space IS our future.
We were not put on this planet to sit on our hands .
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