Hi,
Does anybody remember the "Pyramids of Elysium" from the
Viking Orbiter images? These were 500 to 800 meter three-sided
steep hills clustered in one location. Naturally, there was a
"school of thought" that claimed them as Ancient Alien
Artifacts, great pyramids build by the... yada, yada, yada.
They were ventifacts, of course. The same thing occurs
with lots of small hills in the deserts of Chile. They look
like they might be pyramids, but close up, they are just
hills.
Since all the rocks around Spirit are not shaped like
this, either a) this one is older, or b) this one is softer,
or c) this one came from a different location as most of the
other rocks in the neighborhood.
Sterling
----------------------------------------------------------------------
Dan Wray wrote:
Hello Thomas and group,
Adirondack and many other rocks in the rover photos
appear to be altered by wind erosion. This can leave
very sharp faces and are known as ventifacts. Other
terms used for this effect are dreikanter also
windkanter. Seasonal changes in wind direction can
cause two or three distinct planes on the rock
surface. They are common in windy desert
environments.
Dan Wray
COMETS
----- Original Message -----
From: Thomas Webb
To: Ron Baalke
Cc: [EMAIL PROTECTED]
Sent: Tuesday, January 20, 2004 7:35 AM
Subject: Re: [meteorite-list] Spirit
Drives to a Rock Called 'Adirondack' for
Close Inspection
Ron and List,
Does it appear to you that there may have
been some shearing on the right hand side
of the rock called 'Adirondack'?
Thomas H. Webb
Ron Baalke <[EMAIL PROTECTED]>
wrote:
Guy Webster (818) 354-5011
Jet Propulsion Laboratory,
Pasadena, Calif.
Donald Savage (202) 358-1547
NASA Headquarters, Washington,
D.C.
News Release: 2004-024 January
19, 2004
Spirit Drives to a Rock Called
'Adirondack' for Close
Inspection
NASA's Spirit rover has
successfully driven to its first
target on
Mars, a football-sized rock that
scientists have dubbed
Adirondack.
The Mars Exploration Rover
flight team at NASA's Jet
Propulsion
Laboratory, Pasadena, Calif.,
plans to send commands to Spirit
early
Tuesday to examine Adirondack
with a microscope and two
instruments
that reveal the composition of
rocks, said JPL's Dr. Mark
Adler,
Spirit mission manager. The
instruments are the M�ssbauer
spectrometer and the alpha
particle X-ray spectrometer.
Spirit successfully rolled off
the lander and onto the martian
surface last Thursday. To make
the drive to Adirondack, the
rover
turned 40 degrees in short arcs
totaling 95 centimeters (3.1
feet).
It then turned in place to face
the target rock and drove four
short
moves straightforward totaling
1.9 meters (6.2 feet). The moves
covered a span of 30 minutes on
Sunday, though most of that was
sitting still and taking
pictures between moves. The
total amount
of time when Spirit was actually
moving was about two minutes.
"These are the sorts of baby
steps we're taking," said JPL's
Dr.
Eddie Tunstel, rover mobility
engineer.
"The drive was designed for two
purposes, one of which was to
get to
the rock," Tunstel said. "From
the mobility engineers'
standpoint,
this drive was geared to testing
out how we do drives on this new
surface." Gathering new
information such as how much the
wheels
slip in the martian soil will
give the team confidence for
more
ambitious drives in future weeks
and months.
"Adirondack is now about one
foot (30 centimeters) in front
of the
front wheels," he said.
Scientists chose Adirondack to
be Spirit's first target rock
rather
than another rock, called
Sashimi, that would have been a
shorter,
straight-ahead drive. Rocks are
time capsules containing
evidence of
the environmental conditions of
the past, said Dr. Dave Des
Marais,
a rover science-team member from
NASA Ames Research Center,
Moffett
Field, Calif. "We needed to
decide which of these time
capsules to
open."
Sashimi appears dustier than
Adirondack. The dust layer could
obscure good observations of the
rock's surface, which may give
information about chemical
changes and other weathering
from
environmental conditions
affecting the rock since its
surface was
fresh. Also, Sashimi is more
pitted than Adirondack. That
makes it a
poorer candidate for the rover's
rock abrasion tool, which
scrapes
away a rock's surface for a view
of the interior evidence about
environmental conditions when
the rock first formed.
Adirondack has
a "nice, flat surface" well
suited to trying out the rover's
tools
on their first martian rock, Des
Marais said.
"The hypothesis is that this is
a volcanic rock, but we'll test
that
hypothesis," he said.
Spirit arrived at Mars Jan. 3
(EST and PST; Jan.
4 Universal Time) after a
seven-month journey. In coming
weeks and months,
according to plans, it will be
exploring for clues in rocks and
soil to decipher whether the
past environment in Gusev Crater
was ever watery and possibly
suitable to sustain life.
Spirit's twin Mars Exploration
Rover, Opportunity, will reach
Mars
on Jan. 25 (EST and Universal
Time; 9:05 p.m., Jan. 24, PST)
to
begin a similar examination of a
site on the opposite side of the
planet from Gusev Crater.
JPL, a division of the
California Institute of
Technology in
Pasadena, manages the Mars
Exploration Rover project for
NASA's
Office of Space Science,
Washington, D.C. Images and
additional
information about the project
are available from JPL at
http://marsrovers.jpl.nasa.gov
from Cornell University, Ithaca,
N.Y., at
http://athena.cornell.edu/ .
-end-
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