Scientists discover possible microbe from space
Image of Halley's Comet passing through the Milky Way galaxy. Some scientists believe comets could be vehicles for the spread of organic material throughout the solar system
(CNN) -- An international team of scientists has recovered microorganisms in the upper reaches of the atmosphere that could have originated from outer space, a participant in the study said Friday.
The living bacteria, plucked from an altitude of 10 miles (16 km) or higher by a scientific balloon, could have been deposited in terrestrial airspace by a passing comet, according to the researchers.
The microorganisms are unlike any known on Earth, but the astrobiologists "want to keep the details under wraps until they are absolutely convinced that these are extraterrestrial," said study participant Chandra Wickramasinghe, a noted scientist at Cardiff University in Wales.
| MESSAGE BOARD|
NASA's Ames Research Center posted a cautious reaction to the report on its Astrobiology Web site. NASA said the finding is likely to meet considerable skepticism in the scientific community.
"Aerobiologists might argue that 10 miles is not too high for Earth life to reside, a possibility that Wickramasinghe appears to accept," the statement said.
However, NASA said, a compelling case can be made for the transport of microorganisms through space aboard comets and meteors.
"A recent discovery indicates that microbes can remain dormant for millions of years -- enough time to travel from planet to planet," NASA said.
Disputing critics who suggest that the balloon was contaminated on the ground, Wickramasinghe said the experiment took place with strict controls. He does acknowledge the possibility that terrestrial bacteria could be kicked up into the stratosphere. Living fungal spores have been discovered at altitudes of 7 miles (11 km).
But observations from this and a related study suggest the presence of living bacteria far too high in the atmosphere to have originated from the surface of the planet, according to Wickramasinghe.
"What is present in the upper atmosphere, critics will say it came from the ground. That is a serious possibility at 15 kilometers, but at 40 or 85 kilometers, you can forget about it," he said Friday.
Wickramasinghe and colleague Sir Fred Hoyle published a report on the Web Friday about evidence that they say strengthens the hypothesis that unusual microbes float through the upper reaches of the atmosphere.
Looking at spectral data from the 1999 Leonid meteorite shower, they detected a bacterial "fingerprint" as the tiny space rocks streaked across the sky at a height of 51 miles (83 km).
"The bacteria heated at temperatures high enough to radiate and shine in this (spectral) signature," Wickramasinghe said.
Along with Hoyle, Wickramasinghe pioneered "panspermia," the theory that outer space seeded Earth with its first life forms about 4 billion years ago.
Wickramasinghe holds that primitive life could still be arriving from space. "If we find microbes at great heights that are not contaminants from the ground,
we have to wonder where they came from. One hundred tons of comet and meteor
organic debris is deposited in the atmosphere every day."
Javant Narlikar of India lead the atmospheric bacteria sample study, which the Indian Space Research Organization coordinated.
The location of the microbe is what most impressed Wickramasinghe, not the composition. It seems like a novel strain of a common bacteria genus on Earth, he said.
Mars sample return plan carries microbial risk, group warns
November 7, 2000
Rock hunter finds second Mars meteorite known in U.S.
February 4, 2000
'Nomad' combs no-man's-land for meteors
January 24, 2000
Cardiff Center for Astrobiology
Indian Space Research Organization
Astrobiology at NASA
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.