EXPLORATIONS - Space Digest（在线收听）

EXPLORATIONS - Space Digest
By Paul Thompson

Broadcast: Wednesday, September 15, 2004

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VOICE ONE:

This is Faith Lapidus.

VOICE TWO:

 
Genesis after crash landing in the Utah desert.
And this is Steve Ember with EXPLORATIONS in VOA Special English. Today we tell about the crash of the Genesis spacecraft after three years in space. And we tell about the discovery of three new planets that orbit far-away stars.

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VOICE ONE:

Last Wednesday, September eighth, a spacecraft named Genesis entered Earth's atmosphere high above the western United States. It was traveling at speeds of more than eleven kilometers a second.

The spacecraft was supposed to deploy a parachute at almost thirty kilometers above the surface of the Earth. This special parachute would help the spacecraft slow its great speed. Then helicopters were supposed to catch the parachute before the spacecraft hit the ground. However, the parachute failed to open. Scientists and NASA officials on the ground watched as the two hundred five kilogram spacecraft crashed into the desert surface. It landed at the Utah Test and Training Range.

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The two hundred sixty million dollar spacecraft hit the ground at a speed of more than three hundred kilometers an hour. It hit so hard that it buried itself half underground. The most important immediate concern was the safety of people who worked to recover the spacecraft. The explosive device that was supposed to deploy the parachute had to be made safe before anything could be moved.

 
A scientist examines material taken from Genesis.
As soon as possible, scientists opened the spacecraft. They removed the scientific instruments inside and took them to a special research room. They cleaned the instruments and examined them. Roger Wiens is a member of the Genesis science team. He said first examinations showed major damage inside the spacecraft. However, he said the science team is very hopeful they can still save much of the material collected.

NASA Administrator Sean O'Keefe said the design and strong construction of Genesis may still provide the scientific results they hoped for.

VOICE ONE:

The Genesis project manager is Don Sweetnam of NASA's Jet Propulsion Laboratory, in Pasadena, California. He told reporters that everything had worked extremely well with the Genesis project until the very end. Mister Sweetnam said the Genesis project had plans and special tools for this kind of a problem. He said the scientists will work to recover as much of the science project as possible.

VOICE TWO:

The Genesis spacecraft had been in an orbit almost one and a half million kilometers from Earth for the past three years. Its purpose was to collect extremely small pieces of material from the Sun. Some of the material weighs no more than a few grains of salt.

These small pieces of the sun are invisible ions that flow off the Sun and make up what is called the solar wind. Ions are atoms that do not have many of their electrons.

Scientists will inspect the solar material in special research centers designed to study very small pieces of matter. The research was to have taken several years. Scientists are hoping to find new information in this material about how the Sun and its family of planets came into being and developed.

VOICE ONE:

Scientists have long wanted to capture pieces of matter that come directly from the Sun. While the Sun is mostly made up of hydrogen and helium, scientists believe it also has small amounts of all other elements.

Scientists do not know exactly what the Sun is made of. They hope the Genesis spacecraft will provide evidence of the amounts of chemicals that make up the Sun. They hope this will show how these chemicals resulted in the collection of planets and other bodies in the solar system.

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To find this evidence, scientists had to launch a special spacecraft that could collect matter without interference from other planets. NASA's Genesis spacecraft was launched in August, two thousand one from Cape Canaveral, in Florida.

It was launched into an area of space between the Earth and the Sun where the gravity of both is balanced. There, it collected solar wind material for more than two years from an area in space far from the interfering effects of any planet.

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When the Genesis spacecraft arrived at the correct orbit, it opened the special collectors. The collectors are made of small disks of pure silicon, gold, diamond and sapphire. They collected thousands of millions of atoms from the Sun. In April of this year, the spacecraft began replacing the collectors safely inside the Genesis for the five month long trip back to Earth. The collectors were stored in a round device called a sample return capsule.

In the early morning hours last Wednesday, the sample return capsule separated from the main Genesis spacecraft. The capsule returned to Earth, but crashed into the desert.

Scientists will take any solar matter that survived the crash to a special research center at NASA's Space Center in Houston, Texas. There, scientists from around the world will protect and study the materials for many years to come.

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VOICE TWO:

Researchers have announced the discovery of three new planets in solar systems far from Earth. More than one hundred planets have been discovered in recent years in other solar systems. However, most of these have been huge planets made of gas like Jupiter in our solar system. The new planets are smaller and much more like Earth. They are the closest planets in size to Earth that have ever been found.

 
An artists picture of a new planet.
Researchers say the newly discovered planets are between ten and twenty times the mass of Earth. And, it is possible that they might be made of rock, or rock and ice, instead of gas.

One of the newly discovered planets joins three others that orbit a star named Fifty-Five Cancri. Another planet orbits a star named Gliese Four Thirty-Six. A famous planet-hunting team discovered these two planets. They are Paul Butler of the Carnegie Institute of Washington, Geoffrey Marcy of the University of California at Berkeley and Barbara McArthur of the University of Texas. They announced their discoveries at a news conference at NASA Headquarters in Washington, D.C.

The third planet was discovered by a team led by Michel Mayor of the Geneva Observatory in Sauverny, Switzerland. The European team says the planet they discovered orbits the star mu Arae. That star is about fifty light-years from Earth in the constellation or group of stars called Ara. A light-year is the distance that light travels in one year.

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The two planets discovered by the Americans are thirty-one and forty light-years away from Earth. One is near the constellation Leo and the other is near the constellation Cancer.

The American researchers say the new planets they have discovered are about the size of the planet Neptune. This would make them about seventeen times the mass of Earth. This is still much smaller than other planets that have been discovered. Some of these planets have been seventeen times the size of Jupiter, the largest planet in our solar system.

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The research teams agree that it is unlikely that any of these new planets support life. The planets are too close to the stars they orbit. Temperatures on the surface of the planets are thought to be extremely hot.

But the discovery of these planets is important because they are much smaller than others that have been found. The researchers say it has become easier to find huge planets, but very difficult to find a planet like Earth. An Earth-size planet is much more difficult to see.

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Geoffrey Marcy is a member of the American research team. He says the search for new planets will continue. He says researchers are learning to do a better job finding new and smaller planets. And he says the goal of the American team now is to find planets that are no bigger than ten times the mass of Earth.

Mister Marcy says it is not yet possible to see Earth-sized planets far out in space. But it is possible to see their "big brothers."

Mister Marcy says scientists are searching the stars for answers about our own planet and solar system. They are searching for chemical and biological evidence. Mister Marcy says they are getting closer to answering the question of whether life exists on distant planets.

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VOICE TWO:

This program was written by Paul Thompson. It was produced by Mario Ritter. This is Steve Ember.

VOICE ONE:

And this is Faith Lapidus. Join us again next week for another EXPLORATIONS program in VOA Special English.