EVIDENCE of primitive life on Mars may have been discovered by US scientists, who will reveal their findings at a press conference in Washington today.
In what it terms a startling discovery, the National Aeronautics and Space Administration (NASA) says that examination of a meteorite from Mars, which fell to Earth in 1984, has revealed "exciting, even compelling but not conclusive evidence" of ancient, single cell life on Mars billions of years ago.
The meteorite, found in 1984 in Antarctica, is one of a dozen in a NASA collection believed to have originated from Mars.
Meteorite fragments have been studied extensively under electron microscopes by scientists at the Johnson Space Centre in Houston, Texas.
The NASA research team discovered preliminary evidence of organic material in a meteorite believed to have been blown out of a volcano on the surface of Mars billions of years ago and then cooled on the surface of the planet. "What they've got is a meteorite' which has been altered at fairly low temperatures, and what they are saying is that the alteration may be due to organic activity," said Dr Arch Reid, a geosciences professor at the University of Houston.
When the meteorite was somehow blasted off the surface of Mars and into space it may have carried to Earth the first evidence of life on that planet, Dr Reid said. "The significance is that we have no direct evidence right now other than this possibility that there ever was life on Mars."
Scientists cautioned against people envisioning Hollywood inspired creatures from outer space, saying that the organisms appeared to be more like simple bacteria found on Earth. "I want everybody to know that we are not talking about little green men, said Dr Daniel Goldin, a NASA administrator."These are extremely small single cell structures that somewhat resemble bacteria on Earth. There is no evidence or suggestion that any higher life form ever existed on Mars."
The research team was led by a NASA scientist, Dr David McKay, and included members of a group at the Johnson Space Centre which studies meteorites from Antarctica and rock samples from the Moon. The team also included scientists from Stanford University, the University of California Los Angeles and the Lockheed Martin Corporation.
The scientists had planned to publish their findings in the August 16th issue of Science magazine, but news of the discovery leaked out. They are due to hold a press conference this evening (7 p.m. Irish time) during which photographs of the meteorite will be released.
Mars, which has an average temperature of minus 23 degrees Celsius, contains a number of dried up river beds. It is speculated that subterranean pools probably frozen could have been a source of primitive life forms there.