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This is Faith Lapidus.
VOICE TWO:
And this is Steve Ember withEXPLORATIONS in VOA Special English. Today we tell about a newdevice to explore the polar areas of other planets. We tell aboutvery distant solar systems photographed by the Hubble SpaceTelescope. We have news of a new comet that is moving toward Earth.We begin with the discovery that the planet Mars was once wet enoughto support life.
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On March third, scientists at the American space agency’s JetPropulsion Laboratory in Pasadena, California received exciting newsfrom Mars.
The exploration device Opportunity sent back good evidence thatliquid water once was an important part of the environment of Mars.NASA scientists said the evidence of water suggests that life mayhave once been possible on the red planet. This evidence was foundnear the place where Opportunity landed, known as the MeridianiPlanum.
Steve Squyres is the top expert on the exploration rovers’science instruments. He says Opportunity has gathered enough goodevidence to show there was once liquid water in the area beingexplored. Mister Squyres says liquid water flowed through the rocksthat Opportunity studied. He said the water changed the chemistry ofthe rocks.
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Mister Squyres says this evidence includes minerals that form inthe presence of water. Opportunity’s drilling tool found theminerals when it dug two holes into rocks.
Tests show the rocks contained sulfur and salts in as much asforty percent of their material. Mister Squyres said this isextremely good evidence that the presence of water is stronglylinked with these rocks.
He says there is enough evidence to suggest that it is possiblethat life could have existed in Meridiani Planum. However, he saidOpportunity has not found any direct evidence to suggest that lifewas ever part of the Martian environment.
Mister Squyres says Opportunity is now examining rocks in thearea to see how they were formed. He says they could have been laiddown by minerals that came out of a mixture at the bottom of a saltylake or sea.
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Almost halfway around the red planet, the exploration vehicleSpirit has also found limited evidence of water in the Martian past.Spirit found some evidence of water in a rock at the Gusev Crater.Spirit used its drilling tool to explore the inside of a volcanicrock.
NASA scientists named the rock “Humphrey.” It is about sixtycentimeters tall. Researchers say the evidence of water found inHumphrey is far less than that found by the Opportunity rover.
The scientists want Spirit to explore other rocks for more andbetter evidence. Spirit will drill more deeply into rocks that havenot yet been chosen.
NASA scientists say bothOpportunity and Spirit are returning extremely valuable information.The Spirit vehicle landed on Mars January third. It has been on thesurface of the planet for seventy-five days. Opportunity landedabout halfway around the planet from Spirit on January twenty-fifth.Both vehicles are expected to explore and carry out scientific testsfor about ninety days.
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It is extremely difficult to design a vehicle that will be usedto explore another planet. It is almost as difficult to test such adevice here on Earth. However NASA has built and is testing a newdevice that may one day be used to explore the surface of somedistant planet.
It is called the tumbleweed rover. The device is named after thetumbleweed, a large plant with a round shape. The plant dies andbreaks loose from the ground. Then the wind blows it across thedeserts of the American West.
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NASA’s tumbleweed is a shaped like a large ball. It is almost twometers across. It carries scientific instruments. Scientists aredeveloping the tumbleweed at NASA’s Jet Propulsion Laboratory. Theytested it in January at the National Science Foundation’sAmundsen-Scott South Pole Station.
It rolled across Antarctica’s polar area for eight days. Strongwinds pushed the ball- shaped device across the ice at speeds ashigh as sixteen kilometers per hour. But sometimes there was no windand the device did not move at all. It traveled about seventykilometers during the test.
The average temperature outside was minus thirty degrees Celsius.However, the instruments inside the tumbleweed were kept at aboutthirty degrees Celsius.
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NASA researchers tested the tumbleweed rover in Antarcticabecause of the extremely cold temperatures there. They hope to useit to explore the polar areas of Mars and perhaps other planets.
Alberto Behar is a scientist working on the tumbleweed project.He says the device will be used to explore the polar areas of Marsfor ice. Mister Behar says its instruments will measure airtemperature, pressure, humidity and light and then transmit theinformation back to Earth.
Mister Behar says the ball shape of the device works well inpolar areas. It will be able to use its instruments to find waterbeneath a desert or polar ice. He says scientists are developing anadvanced tumbleweed rover at NASA’s Jet Propulsion Laboratory inCalifornia.
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A comet called C-Two-Thousand-Two-T-Seven is traveling towardEarth. You cannot see it yet unless you have a telescope. Even asmall one will do. You can see the new comet near the planet Venusin the western part of the sky.
For the next three months, the comet will become brighter andbrighter until a telescope is no longer needed. The comet willcontinue moving closer to Earth until May nineteenth. At that timeit might be one of the brightest objects in the night sky. People inthe Southern Hemisphere will be able to see it easily then.
If you have a telescope, now is the best time to see the comet inthe Northern Hemisphere before it begins to move into the southernpart of the sky.
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Another bright object in the night sky is the planet Jupiter.Jupiter recently moved closer to Earth, about six-hundred-millionkilometers away. Jupiter will be very bright during this month. Witha small telescope you can see four of Jupiter’s many moons. You caneasily see Jupiter in the eastern sky after sunset.
March is also a good month for seeing several other planets.Venus is the brightest. It can be seen early in the evening. It iseasy to find and one of the brightest objects in the night sky.Between March twenty-fifth and March thirtieth, you will be able tosee five planets in the early evening sky without a telescope. Theyare Mercury, Venus, Mars, Saturn and Jupiter.
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NASA has released a series of photographs of objects that arefarther away in the universe than anything seen before. The HubbleSpace Telescope took the photographs during several months. Thephotographs include images of about ten-thousand galaxies.
NASA scientists say the photographs show galaxies of many agesand sizes, shapes and colors. They say the larger, brighterphotographs show galaxies as they were more thanone-thousand-million years ago. They say it has taken the light fromthese galaxies that long to reach an area of space where the HubbleSpace Telescope could see it.
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The space telescope took the photographs from one very small areaof the sky. Scientists chose this area because no stars or galaxiescan be seen. The area appears to be empty if seen by telescopes fromthe ground.
Massimo Stiavelli is a researcher with the Space TelescopeScience Institute in Baltimore, Maryland. He was the head of theproject that took the photographs. Mister Stiavelli says the newHubble photographs show an area of space that represents almost thevery beginning of the universe.
Space scientists say the new photographs are very exciting. Theysay the photographs will lead to research that will offer new ideasabout the birth and development of galaxies.
If you have a computer that can link with the Internet, you cansee these beautiful and unusual photographs. Have your computersearch for the word Hubble, HUBBLE, and follow the links.
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VOICE ONE:
This program was written by Paul Thompson. It was produced byMario Ritter. This is Faith Lapidus.
VOICE TWO:
And this is Steve Ember. Join us again next week for anotherEXPLORATIONS program in VOA Special English.