SCIENTISTS and religious thinkers were digesting the news yesterday that traces of organic chemicals - so tiny that thousands would fit on a full stop - are "evidence for primitive life on early Mars".
The news might result in a funding boost for space trips to Mars, and possibly to international efforts to bring back samples from the planet, but religious commentators suggested that the news would make no difference to their beliefs.
The remains were found in a meteorite and appear to be molecules known as PAHs (polycyclic aromatic hydrocarbons), which could have been made by primitive bacteria and single celled organisms. These might have existed billions of years ago beneath the surface of Mars. PAHs are found on Earth in fossil sediments.
The discovery was made at the US space agency NASA by a team of six scientists who found the traces of chemicals deep inside the four billion year old rock. "We don't claim that we have conclusively proven life on Mars'," said one of the scientists, Mr Everett Gibson, at a press conference in Washington. "We are putting this evidence out to the scientific community for other investigators to verify, enhance, attack - disprove if they can - as part of the scientific process." The work will be published next week in the academic journal Science. It built on earlier work by a team at the Open University in Milton Keynes, Buckinghamshire, England. "We have been working on this meteorite, and did some work with the NASA authors," Mr Colin Pillinger, professor of planetary sciences, said yesterday.
The largest fossil is less than a hundredth of the width of a human hair, and most are about a thousandth. Some are egg shaped, others tubular, but the team said they are "strikingly similar" to those from tiny bacteria found on Earth.
The new research could accelerate plans for a manned spaceflight to Mars and attract funds NASA and independent groups say are needed for a thorough exploration. NASA already plans a $150 million (nearly £100 million) trip by an automated spacecraft, due to lift off this November and to land on the planet next July.
Mr Daniel Goldin, a NASA administrator called the discovery "startling". He recently suggested that samples could be brought back from the planet by 2003.
The research does not give any indication of whether any life has survived on Mars, or whether it has evolved. If there is life there, it is probably deep underground perhaps up to 1,000 metres below the surface, which is bombarded with harsh ultraviolet rays and has an average temperature of minus 23 degrees Celsius. "We are not talking about little green men, said Mr Goldin.
However, a number of scientists were wary of welcoming the news in advance of the paper's publication. Mr Christian de Duve, a Belgian scientist who is a Nobel laureate and an expert on life in the Universe, yesterday said: "Obviously this is extremely exciting news, but I don't like to comment without having more information."
Among religious groups, reactions to the suggestion of life on another planet were mixed. A spokesman for the Catholic Church said: "There is no proof yet, but if there were, then it would cause some sort of rethink." A Church of England spokesman said: "We believe that God created the whole universe so I don't think there could be a problem."
Other scientists - including some at NASA - cast doubt on the findings. Mr Jack Farmer, a geologist and paleobiologist of the Exobiology Branch of NASA's Ames Research Centre in California, said: "If that's the evidence, I don't believe it... PAHs have no direct relationship to biology. They are not an indicator.