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Destination:
Gusev Crater On January 3, 2004, NASA's Mars rover Spirit is scheduled to land in a strange crater that might be an ancient martian lake bed. |
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December 30, 2003: On January 3, Spirit, NASA’s 400-pound rover, is scheduled to land on what may be a dried-up lake bed on Mars. “There's not much doubt: this site contained a body of liquid water, at least for some amount of time,” says Jim Garvin, NASA's Lead Scientist for Mars Exploration.
Right: A Mars Global Surveyor image of Gusev Crater. The arrow indicates the direction of possible water flow into the crater. [more] Right now, inside the crater, researchers expect to find sediments, which may be nearly 3,000 feet thick. These sediments, which, researchers hope were deposited by water, may have been covered by dust and sand that’s blown into the crater over the past two billion years.But if there was once water in Gusev, its signature should still be there.
“The Gusev landscape we see today could have been modified by lava, ice, and winds,” he notes. “Aspects of it could have been formed by standing water, or by intermittent floods.” Spirit carries a suite of tools that will find out. The rover will be able to grind away the surface cover on rocks and analyze minerals inside. It will be able to view its surroundings with unprecedented detail and precision. It can scoot over to the most interesting rocks it finds in order to examine them more closely. With these tools and others, Spirit will work to find out what really happened. One clear sign of past water will be in the rocks. For example, if indeed Gusev once held a giant lake (more than 10 times the size of the famous Crater Lake here in the US) certain key minerals are likely to be found in its rocks. Spirit might find evaporites--minerals formed as water dries up. Salt or gypsum are familiar ones here on Earth. Salt’s component parts--sodium and chloride--are separated, dissolved in sea water, but as the water dries up, the sodium and chloride join together to form the mineral “halite.”
Above: An artist's concept of the Mars rover Spirit approaching an interesting rock. [more] On Mars, Spirit might find evaporites like gypsum, or calcium magnesian sulfate. It might also find minerals involving carbonates (i.e., calcium carbonate). These are sometimes, although not always, produced by or from living organisms. But they are almost always a sign of water--“at least here on Earth,” notes Garvin. Another sign will be in the way the sediments are organized. For example,
if the sediments were blown in by winds, the layers may be more erratic,
to reflect the changing directions of airflow (as in fossil dunes here
on Earth). If they were deposited by water, they are more likely to
be layered evenly, one on top of the other in rhythmic stacks. But whatever information Gusev yields will be important. Water or not. Life or not. Whatever it tells us will help determine the course of future explorations on Mars. |
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The
site is Gusev Crater, a 90-mile wide hole in the ground that probably
formed three to four billion years ago when an asteroid crashed just
south of Mars’ equator. There's a channel system that drains into
it, which probably carried liquid water, or water and ice, into the
crater. “It's hard to imagine the landscape looking this way unless
water was somehow involved,” adds Garvin.
| Credits &
Contacts |
Production Editor: Dr. Tony Phillips |
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The Science and Technology Directorate at NASA's Marshall Space Flight Center sponsors the Science@NASA web sites. The mission of Science@NASA is to help the public understand how exciting NASA research is and to help NASA scientists fulfill their outreach responsibilities. |
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Mars Exploration -- (JPL) NASA's home page for exploration of the red planet Carbonated Mars -- (Science@NASA) Here on Earth the only way to make carbonate rocks is with the aid of liquid water. Finding such rocks on Mars might prove, once and for all, that the barren Red Planet was once warm and wet. The Case of the Missing Mars Water -- (Science@NASA) Plenty of clues suggest that liquid water once flowed on Mars --raising hopes that life could have arisen there-- but the evidence remains inconclusive and sometimes contradictory Making a Splash on Mars -- (Science@NASA) On a planet that's colder than Antarctica and where water boils at ten degrees above freezing, how could liquid water ever exist? Scientists say a dash of salt might help. Sedimentary Mars -- (Science@NASA) Mars Global Surveyor images reveal sedimentary rock layers on the Red Planet that may have formed underwater in the distant martian past. Layers
of Mars -- (Science@NASA) Mars Global Surveyor has spotted
terrains on Mars that look like sedimentary rock deposits. If
the mysterious layers formed underwater, as some scientists
suspect, they may be a good place to hunt for Martian fossils. |
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