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EXPLORATIONS - November 7, 2001: Space Digest - 2001-11-06


VOICE ONE:

This is Steve Ember.

VOICE TWO:

And this is Shirley Griffith with the VOA Special English program, EXPLORATIONS. Today we will tell about the spacecraft Mars Odyssey. We will tell about a storm on Mars. And we will tell about the discovery of what may be a very early galaxy.

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VOICE ONE:

The American space agency has received the first picture of Mars taken by the Mars Odyssey spacecraft. NASA officials received the picture last week. It showed the areas of carbon dioxide ice at the southern end of the planet.

NASA official Ed Weiler says that after Odyssey gets into its final orbit it will be much closer to Mars than when the first picture was taken. That picture was taken from about twenty-two thousand kilometers above the south pole of the planet.

VOICE TWO:

The Mars Odyssey spacecraft successfully entered into an orbit around the planet Mars last month. It left Earth six months ago on April Seventh. It flew four-hundred-sixty million kilometers to reach orbit around Mars. NASA officials said it reached its planned orbit with no problems.

Odyssey received radio signals Tuesday, October twenty-third to fire its engines to reduce speed. That action permitted it to be captured by the gravity of Mars.

The gravity caused the spacecraft to enter an orbit that is shaped like an egg. Mars Odyssey orbits the red planet every eighteen and one-half hours.

VOICE ONE:

National Aeronautics and Space Administration Administrator Daniel Goldin said all Americans should be extremely proud of the Mars Odyssey. He said hundreds of things had to be done exactly right for the Odyssey to reach an orbit around Mars. NASA tried two times in Nineteen-Ninety to put another spacecraft in orbit around Mars. Both attempts failed.

For the next three months NASA officials will radio orders to the Mars Odyssey to move it closer to the surface of the planet. They will use the atmosphere to slow the spacecraft and reduce its distance from the surface.

NASA officials will direct the spacecraft to circle the planet every two hours, about four-hundred kilometers above the surface.

VOICE TWO:

Beginning in February, Odyssey will start a two and one-half year science project. The Odyssey spacecraft has several important tasks.

Odyssey does not carry instruments that can search for life on Mars. Yet, it can search for information that will help researchers understand if the environment of Mars can support life now, or if it ever could have supported life.

Evidence of water is extremely important for deciding if life could exist on Mars. Mars is too cold to permit liquid water to remain on the surface. However researchers say water on Mars may be trapped under the surface. It may be ice, or possibly a liquid. Instruments on Odyssey will let scientists measure any amount of permanent ice and how it changes with the seasons.

Odyssey’s instruments will also let NASA scientists search Mars for chemical elements. These elements include carbon, silicon, and iron. Other instruments will help scientists understand how the Martian land developed over time.

VOICE ONE:

Learning what chemical elements are present on Mars will increase understanding of the history of the geology and weather of the planet. Researchers say this information will also help in finding evidence of past or present life on Mars.

Odyssey will seek evidence of radiation on Mars. It will look for possible areas that may be dangerous to future astronaut crews. This information will help NASA know how to plan for a visit to Mars by human explorers.

The Odyssey spacecraft also will support other exploration flights to Mars. The spacecraft will act as a communications link between the surface of Mars and Earth. Odyssey will serve as a communications link between the two NASA Explorations Rover spacecraft that will land and explore Mars. The two Rovers are to be launched a year and one-half from now. An important job for the Two-Thousand-One Mars Odyssey is to search for safe landing areas for future Mars flights.

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VOICE TWO:

The Mars Global Surveyor satellite and the Hubble Space Telescope have provided scientists with close looks at a huge dust storm on Mars. The storm covered the planet. Scientists say it continued for about three months.

James Bell is a scientist who works with the space telescope for Cornell University in Ithaca, New York. He says astronomers had an exciting chance to view an unusual event.

VOICE ONE:

Astronomers say the storm on Mars was much bigger than anything ever seen on Earth. They are studying the effects of the dust storm. One is a sharp increase in the temperature of the Martian atmosphere . This is caused by small pieces of dust that rise high into the air. The sunlight warms the dust, which in turn warms the atmosphere.

Both the Hubble Space Telescope and the Mars Surveyor saw the beginning of the storm toward the end of June. One picture taken by the space telescope shows all of the storm’s activity for one day from sunrise to sunset.

Scientists used the Global Surveyor’s camera to take pictures of the complete planet every day. This permitted them to see where huge amounts of dust had been raised and to see where the dust moved to on the surface of Mars. This series of pictures also permitted them to see how a storm begins and grows as it moves across the planet.

VOICE TWO:

Mike Malin of Malin Space Science Systems in San Diego, California is the lead investigator for the Mars Global Surveyor. The Surveyor has been providing information and pictures of Mars since it began orbiting the planet in Nineteen-Ninety-Eight. It has provided a day-to-day record of climate changes on Mars.

Mister Malin says the two spacecraft have helped scientists learn that the event was not just one continuing dust storm. Instead, it was a planet-wide series of events that began in an area called the Hellas basin.

Mister Malin says that what began as a local event caused other storms to begin and spread many thousands of kilometers away. He said that in less than one week three separate storms were taking place in three main areas of Mars.

The storms began to ease after three months. The dust clouds permitted the surface of Mars to cool. This caused the fierce winds to lessen and the dust to settle back to the surface.

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VOICE ONE:

Scientists have observed light from a very small group of distant stars. They suspect the light may have come from a star system as it was forming. They say the light was released during the first five-hundred-million years after the creation of the universe.

American and European scientists reported the discovery in the publication, Astrophysical Journal Letters.

Richard Ellis of the California Institute of Technology led the study. He says the distant object could be an example of the stars and hot gas needed to make modern galaxies.

Galaxies are the largest gatherings of stars in the universe. In a galaxy, thousands of millions of stars are held together by the force of their gravity.

VOICE TWO:

The scientists made their discovery by examining small areas of sky through a larger group of galaxies. The galaxies are believed to be about two-thousand-million light years from Earth. A light year is the distance light travels in one year.

The scientists say the galaxies helped the distant light appear brighter than it is. To study the light, they used a process called gravitational lensing. Gravitational lensing is an idea developed by the physicist Albert Einstein.

Einstein said a massive object interferes with the normal movement of light through space. A large mass will turn the light from an object behind it. As a result, something behind the galaxies can appear much brighter because the mass in the galaxies directs additional photons toward Earth.

The scientists observed the distant object with the Keck Telescopes in Hawaii. They compared what they saw with two images made by the Hubble Space Telescope.

VOICE ONE:

The effect of gravitational lensing made the light at least thirty times brighter than if the galaxies were not present. Without the increase, neither the Keck Telescopes nor the Hubble Space Telescope would have observed the light.

The scientists then used a spectroscope to measure the energy released. The instrument confirmed the light came from a small galaxy that is extremely distant and in the process of formation.

The scientists found that the system has about one-million stars which are about thirteen-thousand-million light years from Earth. They hope studying it will help them understand the small groups of stars that later helped form present-day galaxies.

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VOICE TWO:

This Special English program was written by Paul Thompson. It was produced by Caty Weaver. Our studio engineer was Mick Shaw. This is Shirley Griffith.

VOICE ONE:

And this is Steve Ember. Join us again next week at this time for another EXPLORATIONS program on the Voice of America.

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