[meteorite-list] 'Blueberries' Are The Answer To Key Mars Puzzle

From: (wrong string) ørn Sørheim <bsoerhei_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:51 2004
Message-ID: <200403171721.SAA24421_at_mail46-s.fg.online.no>

Hmmmm, why didn't anyone think of that in the
first place! :-)
So Opportunity will be driving around on small
globules the rest of the trip on Mars...
Talking about slip slidin away...

Bjørn Sørheim

At 08:27 17.03.04 -0800, you wrote:
>
>
>http://www.newscientist.com/news/news.jsp?id=ns99994790
>
>'Blueberries' are answer to key Mars puzzle
>David Chandler
>New Scientist
>March 17, 2004
>
>The Mars rover Opportunity has now solved the key puzzle it was sent to the
>Meridiani Planum to figure out: where is the hematite that was spotted in
>the area by the Mars Global Surveyor orbiter? The answer is in the
>"blueberries", the tiny mineral spheres that litter the rover's landing
>site.
>
>The question was a key one, because hematite almost always forms in water,
>and water is thought to be a pre-requisite for life. Scientists led by
>Arizona State University's Phil Christensen revealed their discovery at the
>Lunar and Planetary Sciences Conference in Houston, Texas, on Tuesday.
>
>Finding the hematite in the spheres makes sense, because earlier data from
>the rover showed the spheres are almost certainly concretions formed when
>water deposited layer after layer of minerals around a minute grain of sand.
>
>Ever since it landed in January, Opportunity has been seeing more and more
>of the spheres, covering the soil, embedded in the bedrock, and seemingly
>strewn across the flat plateau surrounding the landing crater.
>
>However, until now, nobody knew what they were made of. This was because at
>a few millimetres across they are far too small to fill the field of view of
>any of the rover's three spectrometers.
>
>Berry bowl
>
>The challenge was to find a place where the spheres were sufficiently
>concentrated to provide a target for the spectrometers. A "berry bowl"
>provided the solution, a shallow depression in the bedrock where dozens of
>spheres had collected in a tight bunch.
>
>All three rover instruments, the mini-TES, Mossbauer, and Alpha Proton X-ray
>Spectrometers, as well as its microscope, were used on Saturday and Sunday
>to gather data and provided the definitive evidence.
>
>The surrounding bedrock showed no sign of hematite at all, while the
>concentrated berries showed a very strong signal. It is now clear that,
>while not pure hematite, the spheres contain the primary concentrations of
>the mineral.
>
>They can account for the hematite seen on the soil surface, because they are
>strewn across it, and for its absence in the bounce marks made by the
>rover's landing, because pictures show that all the spheres were driven into
>the soil and out of sight by the force of impact.
>
>Lost lakes?
>
>There is one remaining question about the hematite, however. It appears to
>be even more concentrated on the plains outside the crater. Does that mean
>that there may be an additional source as well, perhaps an overlying layer
>of rock, or just that the plain is strewn with many millions of spheres?
>
>Opportunity is expected to drive out onto that plain in a week or two, and
>should have a chance to answer that question as well.
>
>Christensen, who designed the mini-TES, is hopeful that additional
>hematite-rich formations may be found that might prove the presence not just
>of water, but of large bodies of standing water that may have persisted for
>long periods.
>
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>
Received on Wed 17 Mar 2004 12:21:28 PM PST