MAIN PAGE
WORLD
U.S.
WEATHER
BUSINESS
SPORTS
POLITICS
LAW
SCI-TECH
SPACE
HEALTH
ENTERTAINMENT
TRAVEL
EDUCATION
CAREER
IN-DEPTH
Click Here
QUICK NEWS
LOCAL
COMMUNITY
MULTIMEDIA
E-MAIL SERVICES
CNN ON PDA
ABOUT US
CNN TV
what's on
show transcripts
CNN International
askCNN
EDITIONS
CNN.com Asia
CNN.com Europe
set your edition
Languages --------- SpanishPortugueseGermanItalianDanishJapaneseKorean
Time, Inc. --------- Time.com People Money Fortune EW
Scientist claims 25-year-old data shows signs of life on Mars
July 28, 2001 Posted: 1:31 AM EDT (0531 GMT)
Mars
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
LOS ANGELES (AP) -- Data collected 25 years ago on the surface of Mars by NASA's twin Viking landers show evidence of life, a scientist claimed Friday.
Other scientists quickly cast doubt on the claim by Joseph Miller. They cited a variety of other explanations for the data radioed back to Earth as the landers performed experiments in an effort to find any trace of life on the Red Planet.
Miller, an associate professor in the Department of Cell and Neurobiology at the University of Southern California in Los Angeles, said he detected distinct rhythms in the levels of gas given off during the range of experiments that sought to prompt the growth of microbial life in samples of Martian soil doused with water and nutrients.
The experiments were conducted aboard the robotic Viking landers, which set down on the surface of Mars 25 years ago this month.
If any living organisms were present in the samples, they were expected to process the nutrients and release the carbon they contained in a gas form, which could then be detected.
Gas was released during the experiments, but a majority of scientists have long held it was the result of chemical reactions within the newly moistened -- and highly corrosive -- soil found on the planet's surface.
But Miller said the fluctuations were so regular they resembled the natural day-night, or circadian, rhythms found in terrestrial life forms, including bacteria.
"The most likely explanation is biology," Miller said.
Other scientists regarded the announcement with skepticism.
"The explanation is that there were peroxides that formed in soil, and these are ultimately responsible for reactions, the results of which he saw," said Arden Albee, project scientist on NASA's Mars Global Surveyor mission.
Miller, an expert in circadian rhythms, said he has analyzed about 30 percent of the Viking data. So far, he said, he has found that gas levels produced during the various experiments varied as much as 3 percent during regular periods that matched the length of a Martian day, slightly longer than an Earth day. He said he is "90 percent" sure the results point to the existence of life.
Bruce Jakosky, a professor of geological sciences at the University of Colorado, Boulder, said the regularity could be explained by a number of other reasons, including regular fluctuations in the spacecraft's temperature, the atmospheric pressure on Mars or activity aboard the robotic lander itself.
Miller will present his results on Sunday at an astrobiology symposium held during the International Society for Optical Engineering's 46th annual meeting in San Diego.
Copyright 2001 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
RELATED STORIES:
• Mars orbiter finds traces of past ice age
July 25, 2001
• Remembering Viking at Mars camp
July 24, 2001
• Debate on Mars life rages long after Viking
July 20, 2001
• Mars-mania continues 25 years after Viking
July 19, 2001
• Would life on Mars be this messy?
July 18, 2001
• Manned Mars mission: Rx for problems?
July 18, 2001
• Stargazers gather in Nebraska
July 18, 2001
RELATED SITES:
• Mars Exploration Homepage
• Center for Mars Exploration Home Page
• Mars 2003 and 2005 and beyond
• Mars Today
• Planetary Photojournal: NASA's Image Access Home Page
• Mars Global Surveyor - Welcome to Mars!
• Mars Polar Lander Official Website
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.
SPACE TOP STORIES:
• Scientist claims data shows signs of Mars life
• Star spins so quickly it bulges in middle
• Celestial sites search the sky
• Australian 'scramjet' test flight delayed
• Shuttle causes alarm in Central America
(More)
Search CNN.com CNNSI.com CNNfn.com The Web
Back to the top © 2001 Cable News Network LP, LLLP.
An AOL Time Warner Company. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.