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ZL2VAL > ROVERS 27.02.04 11:33l 109 Lines 5034 Bytes #999 (0) @ WW
BID : AB0565ZL2VAL
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Subj: Opportunity snaps Sunset
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Sent: 040227/0959Z @:ZL2AB.#46.NZL.OC #:36676 [New Plymouth] FBB7.00g
From: ZL2VAL@ZL2AB.#46.NZL.OC
To : ROVERS@WW
NEWS RELEASE: 2004-070
February 26, 2004
Mars Sunset Clip from Opportunity Tells Dusty Tale
Dust gradually obscures the Sun during a blue-sky martian sunset seen in
a sequence of newly processed frames from NASA's Mars Exploration Rover
Opportunity.
"It's inspirational and beautiful, but there's good science in there,
too," said Dr. Jim Bell of Cornell University, Ithaca, N.Y., lead
scientist for the panoramic cameras on Opportunity and its twin, Spirit.
The amount of dust indicated by Opportunity's observations of the Sun is
about twice as much as NASA's Mars Pathfinder lander saw in 1997 from
another site on Mars.
The sunset clip uses several of the more than 11,000 raw images that
have been received so far from the 18 cameras on the two Mars
Exploration Rovers and publicly posted at http://marsrovers.jpl.nasa.gov.
During a briefing today at NASA's Jet Propulsion Laboratory, Pasadena, Calif.,
Bell showed some pictures that combine information from multiple raw frames.
A patch of ground about half the area of a coffee table, imaged with the
range of filters available on Opportunity's panoramic camera, has soil
particles with a wide assortment of hues -- "more spectral color
diversity than we've seen in almost any other data set on Mars," Bell said.
Opportunity is partway through several days of detailed observations and
composition measurements at a portion of the rock outcrop in the crater
where it landed last month. It used its rock abrasion tool this week for
the first time, exposing a fresh rock surface for examination. That
surface will be studied with its alpha particle X-ray spectrometer for
identifying chemical elements and with its Mössbauer spectrometer for
identifying iron-bearing minerals. With that rock-grinding session, all
the tools have now been used on both rovers.
Dr. Ray Arvidson of Washington University, St. Louis, deputy principal
investigator for the rovers' science work, predicted that in two weeks
or so, Opportunity will finish observations in its landing-site crater
and be ready to move out to the surrounding flatland. At about that same
time, Spirit may reach the rim of a larger crater nicknamed "Bonneville"
and send back pictures of what's inside. "We'll both be at the rims of
craters," he said of the two rovers' science teams, "one thinking about
going in and the other thinking about going out onto the plain."
Not counting occasional backup moves, Spirit has driven 171 meters (561
feet) from its lander. It has about half that distance still to go
before reaching the crater rim. The terrain ahead looks different than
what's behind, however. "It's rockier, but we're after rocks," Arvidson
said.
Spirit can traverse the rockier type of ground in front of it, said
Spirit Mission Manager Jennifer Harris of JPL. As it approached the edge
of a small depression in the ground earlier this week, the rover
identified the slope as a potential hazard, and "did the right thing" by
stopping and seeking an alternate route, she said.
However, engineers are also planning to transmit new software to both
rovers in a few weeks to improve onboard navigation capabilities. "We
want to be more robust for the terrain we're seeing," Trosper said. The
software revisions will also allow engineers to turn off a heater in
Opportunity's arm, which has been wasting some power by going on during
cold hours even when not needed.
As it heads toward "Bonneville" to look for older rocks from beneath the
region's current surface layer, Spirit is stopping frequently to examine
soil and rocks along the way. Observations with its microscope at one
wavy patch of windblown soil allowed scientists to study how martian
winds affect the landscape. Coarser grains are concentrated on the
crests, with finer grains more dominant in the troughs, a characteristic
of "ripples" rather than of dunes, which are shaped by stronger winds.
"This gives us a better understanding of the current erosion process due
to winds on Mars," said Shane Thompson, a science team collaborator from
Arizona State University, Tempe.
The rovers' main task is to explore their landing sites for evidence in
the rocks and soil about whether the sites' past environments were ever
watery and possibly suitable for sustaining life. 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
and from Cornell University at http://athena.cornell.edu
=========================
73 de Alan, (Sysop ZL2AB).
AX25:ZL2VAL@ZL2AB.#46.NZL.OC
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Message timed: 22:52 on 2004-Feb-27 (NZT)
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Points to ponder
~~~~~~~~~~~~~~~~
Marriage
~~~~~~~~
You have two choices in life: you can stay single and be miserable,or get
married and wish you were dead
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