[meteorite-list] Deep Space 1 Finds Comet Borrelly Has Hot, Dry Surface

From: meteorites_at_space.com <meteorites_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:24 2004
Message-ID: <20020406081038.8886.h003.c000.wm_at_mail.space.com.criticalpath.net>

Makes me wonder if the C1 carbonaceous meteorites, such
as Tagish Lake are fragments of comet crust.

They often have hydrous minerals that could only been
formed in low temperature environments like the ranges
reported on the surface of this comet.

So, if they get a direct sample of a comet and find
this to be true-- it would not surprise me.

Steve Schoner.
AMS


Ron Baalke wrote

>
>
>
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> Contact: Martha J. Heil (818) 354-0850
  
>
> FOR IMMEDIATE RELEASE April
5, 2002
>
> NASA SPACECRAFT FINDS COMET HAS HOT, DRY SURFACE
>
> Comets are sometimes described as "dirty
snowballs," but
> a close flyby of one by NASA's Deep Space 1
spacecraft last
> fall detected no frozen water on its surface.
>
> Comet Borrelly has plenty of ice beneath its
tar-black
> surface, but any exposed to sunlight has vaporized
away, say
> scientists analyzing data from Deep Space 1, managed
by NASA's
> Jet Propulsion Laboratory, Pasadena, Calif.
>
> "The spectrum suggests that the surface is hot
and dry.
> It is surprising that we saw no traces of water ice,"
said Dr.
> Laurence Soderblom of the U.S. Geological Survey's
Flagstaff,
> Ariz., station, lead author of a report on the
Borrelly flyby
> results appearing in the online edition of the
journal
> Science.
>
> "We know the ice is there," he said. "It's just
well-
> hidden. Either the surface has been dried out by
solar heating
> and maturation or perhaps the very dark soot-like
material
> that covers Borrelly's surface masks any trace of
surface
> ice."
>
> The Deep Space 1 science team released pictures
and other
> initial findings days after the spacecraft flew
within 2,171
> kilometers (1,349 miles) of the comet's solid nucleus
on
> September 22, 2001. This week's report provides
additional
> details about the nucleus and the surrounding coma of
gases
> and dust coming off of the comet as measured by one
of Deep
> Space 1's scientific instruments.
>
> "Comet Borrelly is in the inner solar system
right now,
> and it's hot, between 26 and 71 degrees Celsius (80
and 161
> degrees Fahrenheit), so any water ice on the surface
would
> change quickly to a gas, " said Dr. Bonnie Buratti,
JPL
> planetary scientist and co-author of the paper. "As
the
> components evaporate, they leave behind a crust, like
the
> crust left behind by dirty snow."
>
> Borrelly is unusually dark for an object in the
inner
> solar system. The comet's surface is about as dark as
a blot
> of photocopy toner, possibly the darkest surface in
the solar
> system. It is more like objects in the outer solar
system such
> as the dark side of Saturn's moon Iapetus and the
rings of
> Uranus.
>
> "It seems to be covered in this dark material,
which has
> been loosely connected with biological material."
Buratti
> said. "This suggests that comets might be a transport
> mechanism for bringing the building blocks of life to
Earth."
> Comets may have played an important role in supplying
organic
> materials that are required for life to originate.
>
> Soderblom points out that Borrelly's old,
mottled
> terrain with dark and very dark spots -- different
shades of
> black -- are apparently inactive. Ground-based
observations
> estimated that 90 percent of Borrelly's surface might
be
> inactive, and the observations taken by Deep Space 1
show that
> this is indeed true.
>
> "It's remarkable how much information Deep Space
1 was
> able to gather at the comet, particularly given that
this was
> a bonus assignment for the probe," said Dr. Marc
Rayman,
> project manager of the mission. Deep Space 1
completed its
> original goal to test 12 new space technologies and
then
> earned extra credit by achieving additional goals,
such as the
> risky Borrelly flyby. "It's quite exciting now as
scientists
> working with this rich scientific harvest turn data
into
> knowledge."
>
> Images of comet Borrelly from Deep Space 1 are
available
> at
http://www.jpl.nasa.gov/images/ds1/ds1_borrelly.html .
>
> More information on the Deep Space 1 mission is
available
> at http://nmp.jpl.nasa.gov/ds1/ .
>
> Deep Space 1 was launched in October 1998 as
part of
> NASA's New Millennium Program, which is managed by
JPL for
> NASA's Office of Space Science, Washington, D.C. The
> California Institute of Technology, Pasadena, manages
JPL for
> NASA.
>
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>
>
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Received on Sat 06 Apr 2002 11:10:34 AM PST