Posted on 02/04/2004 6:40:23 PM PST by Phil V.
February 04, 2004
Opportunity Sees Tiny Spheres In Martian Soil
NASA's Opportunity has examined its first patch of soil in the small crater where the rover landed on Mars and found strikingly spherical pebbles among the mix of particles there.
"There are features in this soil unlike anything ever seen on Mars before," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science instruments on the two Mars Exploration Rovers.
For better understanding of the soil, mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., plan to use Opportunity's wheels later this week to scoop a trench to expose deeper material. One front wheel will rotate to dig the hole while the other five wheels hold still.
The spherical particles appear in new pictures from Opportunity's microscopic imager, the last of 20 cameras to be used on the two rover missions. Other particles in the image have jagged shapes. "The variety of shapes and colors indicates we're having particles brought in from a variety of sources," said Dr. Ken Herkenhoff of the U.S. Geological Survey's Astrogeology Team, Flagstaff, Ariz.
The shapes by themselves don't reveal the particles' origin with certainty. "A number of straightforward geological processes can yield round shapes," said Dr. Hap McSween, a rover science team member from the University of Tennessee, Knoxville. They include accretion under water, but apparent pores in the particles make alternative possibilities of meteor impacts or volcanic eruptions more likely origins, he said.
A new mineral map of Opportunity's surroundings, the first ever done from the surface of another planet, shows that concentrations of coarse-grained hematite vary in different parts of the crater. The soil patch in the new microscopic images is in an area low in hematite. The map shows higher hematite concentrations inside the crater in a layer above an outcrop of bedrock and on the slope just under the outcrop.
Hematite usually forms in association with liquid water, so it holds special interest for the scientists trying to determine whether the rover landing sites ever had watery environments possibly suitable for sustaining life. The map uses data from Opportunity's miniature thermal emission spectrometer, which identifies rock types from a distance.
"We're seeing little bits and pieces of this mystery, but we haven't pieced all the clues together yet," Squyres said.
Opportunity's Mössbauer spectrometer, an instrument on the rover's robotic arm designed to identify the types of iron-bearing minerals in a target, found a strong signal in the soil patch for olivine. Olivine is a common ingredient in volcanic rocks. A few days of analysis may be needed to discern whether any fainter signals are from hematite, said Dr. Franz Renz, science team member from the University of Mainz, Germany.
To get a better look at the hematite closer to the outcrop, Opportunity will go there. It will begin by driving about 3 meters (10 feet) tomorrow, taking it about halfway to the outcrop. On Friday it will dig a trench with one of its front wheels, said JPL's Dr. Mark Adler, mission manager.
Opportunity's twin, Spirit, today is reformatting its flash memory, a preventive measure that had been planned for earlier in the week. "We spent the last four days in the testbed testing this," Adler said. "It's not an operation we do lightly. We've got to be sure it works right." Tomorrow, Spirit will resume examining a rock called Adirondack after a two-week interruption by computer memory problems. Controllers plan to tell Spirit to brush dust off of a rock and examine the cleaned surface tomorrow.
Each martian day, or "sol," lasts about 40 minutes longer than an Earth day. Spirit begins its 33rd sol on Mars at 2:43 a.m. Thursday, Pacific Standard Time. Opportunity begins its 13th sol on Mars at 3:04 p.m. Thursday, PST.
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, Ithaca, N.Y., at http://athena.cornell.edu .
### Guy Webster (818) 354-5011 Jet Propulsion Laboratory, Pasadena, California
Donald Savage (202) 358-1547 NASA Headquarters, Washington, D.C. NEWS RELEASE: 2004-051
What's interesting to note as well is that nothing beats keeping muscle tone like gravity. Even workouts in space do little to combat the atrophy.
Worse still is the degenerative effect on the skeletal structure. Calcium loss by the bones occurs at 1% a month (a rate 10 times faster than in osteoporosis).
If we are to have extended missions, we are going to need to simulate gravity somehow. And generating a 32 fps downward velocity takes some doing.
Ah, you mean I'm not the only Freeper who's annoyed that the stereoscopic pictures are always reversed from the way they should be? "Relax your eyes & let the images merge" indeed! Are we the only people who know how to cross their eyes?
Odd shape for a rock. Could be part of the lander or airbag.
I have heard that you don't need to simulate 1g, something smaller should do. Also, it might not be neccessary to simulate it for the entire trip, just portions of it.
That is true. Even half a G would do.
Also, it might not be neccessary to simulate it for the entire trip, just portions of it.
Ew. That'd be naaaaaasty. Ever read about the changes the body goes through in going from normal gravity to microgravity? It ain't pretty and the adjustment period is unpleasant and disorienting in many ways. I think it'd be better to have gravity as a constant the whole way rather than making the crew go through readjustments several times in the journey.
DIATOMS: Any of various microscopic one-celled or colonial algae of the class Bacillariophyceae, having cell walls of silica consisting of two interlocking symmetrical valves.
I am just amazed at this statement. ANYTHING is going to be unlike anything else ever seen on Mars before. Hardly anything on Mars has ever been seen on Mars before. Jeezo!
Your cheapo camera has a program that converts raw data to colors intended to look pleasing. Those colors would be completely useless for analysing the composition of the various rocks and sediment. The NASA cameras are calibrated, as are the color filters, so that with time and care, the actual colors can be recreated.
As for the rest:
Is it because some of the resolution had to be sacrificed for durability in extreme conditions?
the article says: "The CCD chip also has extremely large 'storage wells' behind each pixel. The chip can store a little more than 200,000 electrons in each well, Wadsworth [the designer] said, compared with perhaps 20,000 for a commercial digital camera. Larger well sizes help the camera cope with radiation and also with the extreme temperature range, since thermally generated background charge can fill the wells."
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