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VOICE ONE:
This is Shirley Griffith.
VOICE TWO:
And this is Steve Ember withEXPLORATIONS in VOA Special English. Today we complete our twoprograms about exploring the planet Mars. We tell about the twovehicles that have landed successfully on the Red Planet and areexploring the surface for evidence of water and life.
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VOICE ONE:
People on Earth have always been interested in the planet Mars.Recently, that interest has increased because several successfulspacecraft have been placed in orbit around Mars. These include theAmerican space agency’s Mars Global Surveyor and Mars Odyssey andthe European Space Agency’s Mars Express.
Each of these spacecraft has increased our knowledge of Mars.Each has sent back huge amounts of scientific information andphotographs of the planet. The National Aeronautics and SpaceAdministration has given that information and photographs to thepublic on the Internet computer system. This too has increasedpublic interest in Mars.
VOICE TWO:
Perhaps the most exciting event took place on January third. Thatis when the first of two Mars exploration vehicles successfullylanded on the Red Planet. The first lander is named “Spirit.” Itcame to rest in an area of Mars named Gusev Crater. Millions ofpeople used their computers to link with NASA’s Internet Web site tosee photographs sent back by Spirit.
VOICE ONE:
On January fifteenth, NASA scientists told Spirit to use its sixwheels to move off the landing device. It did this successfully androlled on to the surface of Mars. Excited NASA officials said Spiritwas now ready to begin its task of exploring the surface of the RedPlanet.
Scientists on Earth sent commandsto have Spirit move to a rock that could be clearly seen inphotographs. It did this successfully. Spirit continued to send backphotographs and valuable information.
On January twentieth, scientists told the exploration rover touse one of its tools to study the soil near the rock. The next day,Spirit began having problems. It answered radio signals, but itwould not send back scientific information.
NASA officials began to work to correct the problem with Spirit’scomputer. The part of the computer that stores information was notworking correctly. On February first, NASA announced that Spirit’scomputer memory had been successfully repaired. It will beginscientific examinations of rocks later this week.
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VOICE TWO:
On January twenty-fourth, the second rover device reached thesurface of Mars. It too immediately began sending back photographsof a very different area of Mars. Public interest in Mars increasedagain.
The second vehicle is named “Opportunity.” It landed in an areaof Mars called Meridiani Planum. NASA scientists say Opportunitylanded inside a large hole in the surface of the planet.
Photographs from Opportunity show several large formations ofrock. The photographs clearly show this rock is below the surface.NASA scientists say the rock they see in the photographs is not likeanything they have ever seen before.
On January thirty-first, Opportunity moved off its landing deviceand on to the surface of Mars. NASA officials say it will examinesoil in front of it for the next several days.
Steve Squyres is a scientist atCornell University in Ithaca, New York. He is the chief investigatorfor science instruments on both Opportunity and Spirit. He says theareas where the two devices landed are very different. He saysOpportunity landed in a very strange and wonderful area forscientific investigation.
He says that scientists are extremely excited about the MeridianiPlanum area. Mister Squyres says it is good that Opportunity landedin a hole. It will be able to explore areas below the surface of theplanet without having to dig.
He also says the hole is not deep. This means when Opportunity isdone exploring this important area it will be able to drive out ofthe hole with little or no problems. It will then be free to exploreother areas.
VOICE ONE:
NASA officials say they have discovered and confirmed thatOpportunity landed on an area of Mars that is rich in the mineralcrystalline hematite. On Earth such hematite usually forms in thepresence of water. Scientists want to know if the hematite on Marswas formed under water too.
Some evidence suggests that long ago the Meridiani Planum area ofMars was wet and held water. Opportunity will search for moreevidence of water and any evidence that some kind of life could haveexisted in the area.
The Meridiani Planum where Opportunity landed and Gusev Craterwhere Spirit came to rest are very different. They were bothcarefully chosen from among one-hundred-fifty areas on Mars.
NASA officials were able to make the choice using photographs andinformation supplied by the Mars Global Surveyor and Mars Odysseyspacecraft. Both are in orbit around the planet.
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VOICE TWO:
The Spirit and Opportunity exploration vehicles carry specialscientific equipment to learn many of the secrets of Mars. Bothvehicles are exactly the same. Each weighs one-hundred-seventy-fourkilograms. Each carries several cameras. But the cameras are usedfor different purposes.
One camera is used to see where the vehicle is going. It searchesfor a clear path that is free of major objects.
Another camera takes extremely detailed color photographs. It cantake photographs in a complete circle around the explorationvehicle. One camera is inside a microscope that can see objects assmall as a human hair.
Batteries provide power for the exploration rovers. The batteriesstore power they receive from special solar collectors that changesunlight into electric energy.
VOICE ONE:
The exploration rovers carry communications equipment thatpermits them to communicate directly with Earth. They can alsocommunicate with the Mars Global Surveyor satellite in orbit aroundthe planet. The Surveyor satellite can pass on information itreceives from the rovers.
Each rover carries a special computer that can survive in theextremely cold temperature of Mars. The computers can also surviveextreme amounts of radiation.
VOICE TWO:
The rovers each carry a science instrument called the AlphaParticle X-Ray Spectrometer. This instrument can be placed on rocksand soil to study the chemicals inside.
Another tool is called the Thermal Emissions Spectrometer. Thistool studies minerals in rocks and soil from a distance by measuringthe amount of heat radiation they release. It can also study theplanet’s atmosphere.
Devices called Capture-Filter Magnets can capture and hold dustthat contains small amounts of iron. The other scientificinstruments can then study this dust.
One of those instruments is the Mossbauer Spectrometer. Thisinstrument is designed to study minerals that have large amounts ofiron.
Spirit and Opportunity each carry a Rock Abrasion Tool. This is apowerful machine that uses electric motors to grind away the surfaceof rocks so the inside material can be inspected and studied. Thisis done with the microscope camera and other scientific instruments.
VOICE ONE:
Mister Squyres says all of the science instruments make the twovehicles into mechanical scientists. He says they use their colorcameras and infrared instruments to study rocks and interesting soilat a distance. The vehicles then are commanded to go to the rocks orareas of soil that seem most interesting.
When they get to an interesting area they reach out with amechanical arm that carries several tools. The arm carries themicroscope, two instruments for identifying what the rock is made ofand a tool for cutting into the rock.
Scientists say that Spirit and Opportunity will explore thesurface of Mars for as long as ninety days. The rovers will beexploring the surface in an effort to find evidence of water onMars. Water is extremely important to any future human explorationof Mars.
The two devices are trying to discover if we have not been alonein the universe. They are trying to answer the question: Is thereany evidence that life once existed on the Red Planet?
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VOICE TWO:
This Special English program was written by Paul Thompson. It wasproduced by Mario Ritter. This is Steve Ember.
VOICE ONE:
And this is Shirley Griffith. Join us again next week for anotherEXPLORATIONS program on the VOICE OF AMERICA.