[meteorite-list] Mars Rover Discovers A Potential Meteorite

From: Tom AKA James Knudson <peregrineflier_at_meteoritecentral.com>
Date: Sat Jan 15 10:26:49 2005
Message-ID: <003701c4fb16$9ce1ea00$2d107918_at_Michelle>

Hey List, Nininger said there should be ten meteorites on every square mile
of earth. The rate, I would think would be higher on mars, with a less dense
atmosphere. Without the weathering and such, I would think the meteorites
would stay in one place and survive a lot longer, so I would think the
rovers should be able to find them all over the place. But, what do I know?
: )

Thanks, Tom
peregrineflier <><
IMCA 6168
http://www.frontiernet.net/~peregrineflier/Peregrineflier.htm
----- Original Message -----
From: "Sterling K. Webb" <kelly_at_bhil.com>
To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
Sent: Friday, January 14, 2005 11:23 PM
Subject: Re: [meteorite-list] Mars Rover Discovers A Potential Meteorite


> Hi,
>
> I have nothing to contribute as to whether the object is or is not a
meteorite, but there is one thing
> about discovering a meteorite on Mars that disturbs me.
> The performance of the rovers have greatly exceeded their planned
lifetime and reach, but even so, the
> two them have only covered a few thousands of meters. Assuming that their
cameras only scan closely
> objects within a few hundred meters of their position as they move along,
the total land area scanned in
> detail by the rovers can only amount to one square kilometer or maybe two.
(Five kilometers of travel
> times 200 meters of total sideview equals one square kilometer.)
> What are the odds of finding a good-sized meteorite in ANY 1 or 2
square kilometers? Since we can
> assume the choice of Martian location is random, let's re-phrase that to:
What are the odds of finding a a
> good-sized meteorite in EVERY 1 or 2 square kilometers of Mars?
> Frankly, it would mean that meteorites are incredibly abundant on
Mars. It would mean a very high fall
> rate. It would mean meteorites survive for a very long time in the Martian
environment. But one big
> meteorite per square kilometer would mean that Mars has tens of millions
of big meteorites on its surface.
>
> And by the normal power law distribution, there should be hundreds of
millions of meteorites 1/3 this
> size and billions 1/10th this size and a million meteorites three times
this size, and so on. That's a
> helluva lot of meteorites! (And you thought NWA's would flood the
market...)
> Or maybe the rovers are just incredibly lucky meteorite hunters? (Can
I rent one?)
> Yes, it could just be a fluke, wild luck, like winning the lottery,
but the entire mission (despite
> being targeted at potential formerly wet sites), like all missions, is
based on the principle that a
> random sample is in the long run a representative sample.
> So, it sits there on its sand dune. If that sand dune were one square
kilometer of North West Africa
> picked at random, what are the odds there'd be a meteorite sitting on it?
> Is it too good to be true?
>
>
> Sterling K. Webb
> --------------------------------------------------------------
> At 04:24 PM 1/14/2005, Ron Baalke wrote:
>
> > >
> > >
> > > >http://www.newscientist.com/article.ns?id=dn6883
> > > >
> > > >Mars rover discovers a potential meteorite
> > > >Kelly Young
> > > >New Scientist
> > > >January 14, 2005
> > > >
> > > >NASA's rover Opportunity has spotted an unusual rock on Mars that may
be
> > > >a meteorite.
> > > >
> > > >The rover first glimpsed the rock two weeks ago as it approached the
> > > >remains of its heat shield, which plummeted to Mars during the
rover's
> > > >descent through the atmosphere in January 2004.
> > > >
> > > >The object, about the size of a potato, caught the eyes of ground
> > > >controllers because of its unusual pitted surface. "We've been seeing
> > > >little rocks on the plain since the start of the mission," says
Steven
> > > >Squyres at Cornell University, the Mars rovers' chief scientist. "We
all
> > > >just kind of assumed they're little pieces of Martian basalt."
> > > >
> > > >But Opportunity's infrared spectrometer, called Mini-TES, saw that
this
> > > >object did not radiate thermal energy at the frequencies expected of
> > > >"typical" Martian rocks, leading scientists to hypothesise that the
> > > >object might in fact be a meteorite rich in metal.
> > > >
> > > >Opportunity has stayed next to the object and will continue making
> > > >measurements over the weekend to confirm whether this is indeed a
> > > >meteorite. Squyres says they should have the results by Monday or
> > > >Tuesday. "It could be any number of things if somehow we got faked
out
> > > >by the Mini-TES data," Squyres cautions.
> > > >
> > > >Unexpected circumstances
> > > >
> > > >Meteorites are objects that survive the - sometimes fiery - fall to a
> > > >planet's surface from space. Only about 2% of the meteorites that
land
> > > >on Earth are made of nickel and iron. The rest are made of rock.
> > > >
> > > >Squyres says that the rover's rock abrasion tool, which is used to
grind
> > > >away the surface of rocks, had never been tested against a metal like
> > > >nickel. "I didn't see this coming," he told New Scientist.
> > > >
> > > >Opportunity will celebrate its first birthday on the Martian surface
on
> > > >25 January. So far, it has trekked over 2000 metres around Meridiani
> > > >Planum and recently weathered its first dust storm.
> > > >
> > > >Opportunity's twin rover, Spirit, has been roaming around the other
side
> > > >of the planet on an area called Husband Hill, but it has had trouble
> > > >getting around because its wheels have been slipping on the sandy,
> > > >sloped surface. Ground controllers have also been monitoring a
> > > >fist-sized rock which has become stuck in the wall of Spirit's wheel.
> > > >
> > > >
>
>
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Received on Sat 15 Jan 2005 10:26:40 AM PST