|
|
NASA to revise space missions to focus on Mars findings
August 7, 1996
Web posted at: 9:15 p.m. EDTWASHINGTON (CNN) -- NASA is challenging the world's scientists to examine its case that some form of life existed on Mars billions of years ago, and the United States is taking another look at its space-exploration goals.
Before NASA's announcement Wednesday on its Mars findings, the agency already was planning to send 10 spacecraft to the planet over the next decade to learn more about it.
The missions are still a go: One spacecraft is to be launched in November and the other in December. In the second, the Mars Pathfinder mission, the craft is scheduled to land on July 4, 1997. Its goal is to put a land rover on the planet's surface. (1.5M QuickTime movie)
But plans for some of the missions will be revised to try to prove or disprove whether primitive life ever existed on Mars, NASA Chief Administrator Dan Goldin said Wednesday. (371K AIFF or WAV sound)
Goldin said that a robot mission to return samples from Mars will not be mounted before 2005.
NASA scientists offered evidence Wednesday that there may have been microscopic life on Mars about 4 billion years ago.
NASA scientists theorize that an asteroid smashed into Mars 15 million years ago, knocking pieces of the planet into space. About 13,000 years ago, one of those chunks landed at Earth's South Pole. Researchers found tubular structures lodged in the clay inside the meteorite, which NASA believes are fossilized bacterial forms 3.6 billion years old.
The scientists are being very careful to say that is only their opinion.
"They could be microfossils from Antarctica or microfossils from Mars," said NASA's David McKay of the Johnson Space Center in Texas. "It is our interpretation, the one that we favor, is that these are in fact microfossils from Mars."
Members of the scientific team that compiled the data on the potato-sized meteorite -- picked up in 1984 from an Antarctic ice field where it had lain for 13,000 years -- explained the painstaking process used to make their determinations.
Step by step research
First, they determined the meteorite was from Mars by comparing its chemical structure with data on the Martian surface collected by NASA's Viking explorer 20 years ago. Then, using electron microscopes and laser mass spectrometry, the scientists compared the microscopic shapes and forms on the meteorite with those of known microfossils on Earth.
Stanford scientists demonstrate laser mass spectrometry
"There are alternative explanations for each of the lines of evidence," McKay said. "But when you look at them all together, collectively, we conclude that this is evidence for early life on Mars."
William Schopf, an expert on ancient bacteria from the University of California - Los Angeles, said the NASA team scored well in proving the source and age of the rock, and in proving the presence of organic material.
Schopf, who did not participate in an analysis of the meteorite, called the report a "fine piece of work," but said he regarded it as "a preliminary report."
"It is exciting, interesting, pointing in the right direction," he said. "But additional work needs to be done."
President Clinton termed the discovery "stunning," and pledged that the U.S. space program would "put its full intellectual power and technological prowess behind the search for further evidence of life on Mars." (130K AIFF or WAV sound)
Clinton reiterated his support for the planned unmanned trips to Mars, and called on Vice President Al Gore to convene a bi-partisan summit in November to discuss the future of the U.S space program.
Findings significant
The scientists on NASA's team were clearly elated, although cautious, about their discovery. If their evidence is borne out, the implications are far-reaching.
"What it means is that life originated on a planet other than our own early in its history," Wes Huntress of the Johnson Space Center said. " ... And if it originated in this solar system -- and on more than one planet in this solar system -- why wouldn't it have originated in some other solar system?" (734K AIFF or WAV sound)
The significance of the findings, Goldin said, call for further research to corroborate the results, including taking more samples from the planet via robotic and, later, human exploration. (452K AIFF or WAV sound)
But while he tries to be skeptical, Goldin is clearly thrilled with the idea that something like this could happen on his watch.
"This is wonderful research ... it didn't take billions to do this research, it took dedication and brilliant minds and we have 10 spacecraft scheduled to go to Mars in the next 10 years. It's there. We'll see results year after year and the American people will share it with us."
Reporter Jim Slade and The Associated Press contributed to this report.
|
Tell us what you think!
You said it...
© 1996 Cable News Network, Inc.
All Rights Reserved.