EVIDENCE OF LIFE FOUND IN SECOND MARS METEORITE Written by Ron Baalke November 1, 1996
In a press conference yesterday, scientists in England claimed that they've found traces of organic material in a second Mars meteorite, EETA 79001. The same team also reported that they've found organic matter in the ALH 84001 meteorite, the same meteorite that a NASA team reported last August as having possible microfossils. A critical finding by the British team is that EETA 79001 contains significant amounts of organic material, up to 1,000 parts per million. This organic material has yet to be identified. The British team consists of Ian Wright and Colin Pillinger from Britain's The Open University, and Monica Grady from London's Natural History Museum.
The EETA 79001 meteorite was found in Elephant Morraine in the Antarctic, and was the first meteorite found during the 1979-1980 collecting season. EETA 79001 is classified as a shergotite, the most common subgroup of the Mars meteorites. EETA 79001 weights 7,900 grams (17.4 pounds), and is the second largest Mars meteorite ever found - only the Zagami meteorite is larger. What makes the findings from the British team particularly exciting, is that EETA 79001 is much younger than ALH 84001. EETA 79001 is only 180 million years old - very young on the solar system scale - and was launched into space from Mars 600,000 years ago. The young age of this meteorite suggests that life existed on Mars much longer than what was previously thought, and that there is a possibility that life could still exist on Mars today.
For more info on Mars meteorites, see the Mare Meteorite home page:
Ron Baalke | baalke@kelvin.jpl.nasa.gov Jet Propulsion Lab
UK News Electronic Telegraph Friday 1 November 1996 Issue 527
I found life on Mars seven years ago, says Briton By Roger Highfield, Science Editor
Life on Mars was found by Britons - and it's still there
THE scientist who was billed as missing the biggest discovery of the century - evidence of life on Mars - yesterday expressed quiet satisfaction that his team may well have beaten NASA to the prize seven years ago.
The announcement in August that primitive organisms may once have lived on Mars was made by American scientists who had analysed the Martian meteorite ALH (Allan Hills) 84001 - named after the site where it was found in Antarctica.
Prof Colin Pillinger, of the Open University, had also intensively studied the meteorite and drawn a blank when it came to evidence of life. Now crucial confirmatory evidence of life has come from work on ALH 84001 and another meteorite, conducted by his team in the past few weeks.
The study was presented yesterday to an elite group of scientists attending a Royal Society meeting entitled Searching for Life in the Solar System and Beyond.
On the day in August when Dr Everett Gibson and Dr David McKay of NASA made their sensational announcement, Prof Pillinger told me: "Why did we miss it? You know as well as I do that science is progressive and, for a subject as important as Martian meteorites, everybody wants you to prove, as you go step by step, that you have not contaminated it with terrestrial organisms."
He had good reason to be concerned by contamination, for that was the reason that his earlier research providing evidence of life, which predated NASA by seven years, had been doubted. In 1989, Prof Pillinger and husband-and-wife team Dr Ian Wright and Dr Monica Grady, now of the Natural History Museum, reported in the journal Nature that they had found a high proportion of organic material, including the mineral carbonate, deep within EETA 79001 meteorite, and concluded it was the first such evidence, with "obvious implications".
The rock, found in 1979, was from the same class as ALH 84001 and is also thought to have been ejected from Mars, though much more recently - 600,000 years ago - as revealed by its exposure to cosmic rays. Eventually it fell to Earth to be preserved in pristine condition in Antarctica.
Organic - carbon-based - molecules are the requisite building blocks of life on Earth and "we had a job convincing people there was carbon in there at all and that it was not contamination," said Prof Pillinger. He referred to an analysis of carbon isotopes conducted at the University of Arizona that suggested as much.
"It was a sword of Damocles that hung over us for a long time."
Yesterday, however, crucial confirmation that their 1989 work had been correct was presented to the meeting. "If you apologise for telling the world that I missed it, that would be very nice," he told me afterwards.
The crucial experiments involved heating up samples of meteorite - plotting the amount of carbon released (in parts per million per degree C) and the isotopic composition of the isotopes - to temperatures of 1,200 deg C. This plot can reveal a great deal about the composition.
The plot showed EETA 79001 did indeed contain organic material, up to 1,000 parts per million. "The carbonates in 79001 are associated with organic compounds, massive amounts of organic compounds," Dr Wright said yesterday. "Where we are looking in these rocks now, including 84001, we seem to find an association between the two. Wherever you find high amounts of carbonate, you find high amounts of organic compounds so that whatever process put the carbonates in put the organic compounds in."
Crucially, however, EETA 79001 is only 180 million years old, unlike ALH 84001's 3.6 billion years. From what is known about the meteorite, for instance the time took to travel to Earth, Prof Pillinger said it shows that life could have thrived on Mars between 600,000 years ago and 180 million years ago, when the rock crystallised.
In the case of EETA 79001, the team has not got all the evidence stacked up by NASA scientists for ALH 84001. But "we have a couple of pieces and they are the same. The difference is that these were formed in the first half-a-billion years, which is very recent," said Dr Wright.
Dr David DesMarais, who represented NASA at yesterday's meeting, asked if the British had beaten his team, said: "They made a very important contribution. The reason the more recent work on ALH 84001 was done was largely on the encouragement of the earlier work the Brits and others have done on Martian meteorite. The definitive statement on such things comes from more than one laboratory, and additional lines of evidence," he said.
"All of these findings suggest that Mars has preserved very well a record of organic material which is required to make an interpretation about the presence or absence of life."|
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