[meteorite-list] Mars Rovers See Earth, Moon and Stars
From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:48 2004
Ron and others:
I have to agree with Mark Ford in that the news briefs coming out of these NASA announcements about the rover status (and the music played to each one) tells us almost nothing about what
they are finding up there. Is the information somewhere else on the net that we can go and read
up on. I mean are they finding the typical SNC type rocks as we know them, or variations on
these igneous rocks? Is there more out there on the sedimentary stuff, etc.
To me these stories are saying very little about what they are finding. Maybe that is
intentional so that novices like myself don't jump to any off-based conclusions.
I love classic rock but I'm bored with most of these non-technical Rover story-lines.
> Mars Rovers See Earth, Moons and Stars
> By Robert Roy Britt
> 11 March 2004
> The Spirit rover on Mars took the first picture of Earth ever made from the
> surface of another planet. It also did a little astronomy, imaging bright
> It also spotted what could be a Viking Orbiter spacecraft or a meteor --
> scientists aren't sure which.
> The photo of Earth shows the planet as a bright dot above the horizon about
> an hour before sunrise. The image is not in color, though scientists say if
> a human stood in the same spot and looked earthward, home would probably
> appear pale blue.
> On the other side of the planet, Opportunity captured animated images of
> Mars' moon Phobos eclipsing the sun. This, along with the previous image of
> Deimos' solar eclipse, will help astronomers pin down the small moons'
> orbits around the planet. Mark Lemmon, a rover science team member from
> Texas A&M University, said Phobos' orbital position is uncertain, with its
> actual route varying by about 6 miles (10 kilometers), which is roughly the
> size of the moon itself.
> Knowing Phobos' exact orbital path would allow satellites orbiting Mars to
> obtain close-up photos of the moon. Researchers do not know if the moons
> formed along with Mars or are captured asteroids.
> Stars and streaks
> Spirit is also seeing stars. The rover took nighttime images in the
> direction of the constellation Orion. The bright star Betelgeuse is visible
> in the upper right. Orion's belt, a row of three bright stars, can be seen
> near the bottom of the photograph.
> Faint specks on the image are the result of cosmic rays hitting the camera,
> Lemmon said.
> None of Spirit's astronomy images are part of the rover's primary mission,
> but by taking more of them, scientists hope to learn something about the
> amount of dust and water vapor in the nighttime atmosphere of Mars.
> Another sky photo from Spirit shows a thin and short streak of light.
> "That streak could have been a meteor," Lemmon said. Or it could have been
> the Viking Orbiter 2, still circling Mars long after its 1970s mission
> ended. Lemmon said the other nine spacecraft currently orbiting Mars --
> three of which are presently in working order -- have known positions and
> did not create the streak.
> Spirit reaches Bonneville
> Meanwhile, carrying out its day job, Spirit has finally peered down into an
> impact crater called Bonneville. It is the first view of a good-sized impact
> crater on Mars ever taken from this vantagepoint, said Matt Golombek of
> NASA's Jet Propulsion Laboratory (JPL).
> The crater does not appear to harbor any sedimentary rock outcroppings, like
> what was found at the Opportunity landing site, Golombek said at a press
> conference today. Instead, the rocks around the rim appear to all be similar
> to rocks the rover has encountered running up to the rim. They are all
> thought to have been cast out by an ancient impact.
> The lack of outcroppings of bedrock is somewhat of a disappointment for
> scientists, because it suggest there might not be any easy-to-find signs of
> standing water at the Spirit site. The craft has found signs of past water
> associated with volcanic activity, but not the sort of soggy situation
> revealed by Opportunity.
> Spirit will explore the crater rim for a week or two before deciding whether
> to drive down in or move on toward the distant East Hills. The decision will
> be made based on both science and rover safety.
> On the other side of the planet, the Opportunity rover is in the process of
> analyzing the "blueberry bowl," a high concentration of BB-sized spheres.
> Scientists are confident the spheres, which they sometimes call blueberries,
> formed in water, but they don't yet know their composition.
> Hematite was water-generated
> One of Opportunity's next tasks will be to further investigate a mineral
> called hematite, which is abundant on the plains that surround the shallow
> depression in which the robot landed. Phil Christensen of Arizona State
> University in Tempe said the latest infrared observations show the hematite
> is highly concentrated in hot spots.
> "We call them the mother lode of hematite," Christensen said. The hotspots
> suggest the hematite has been on the plains for perhaps a billion years and
> has been broken up from an original rock. He also figures the hematite was
> long ago punched out of the landing-site crater, which contains very low
> quantities of the mineral.
> Over the eons, some hematite has been transported back down into the shallow
> crater, but "that's a very slow process," he said.
> On Earth, hematite usually forms in the presence of standing water.
> Scientists had sought to determine if water was the source of the Martian
> hematite, which had first been detected from orbiting spacecraft and was one
> reason Opportunity's landing site was picked.
> Given the discovery of past water at Opportunity site announced earlier this
> month, "I think it's fair to say the hematite also formed in water,"
> Christensen said. His team will now try to find out how the hematite fits
> into the overall story of past water on Mars.
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Received on Thu 11 Mar 2004 10:32:36 PM PST