25 years ago, at least for a moment, even the President of the United States thought they had found alien life.
On 7 August 1996, President Bill Clinton addressed the nation concerning the findings of a group of NASA and Stanford scientists. The scientists had found what they believed to be signs of microbial life in a meteorite determined to be of Martian origin. Most definitely an OMG moment in the White House!
ALH 84001, more colloquially known as the Alan Hills meteorite, would go on to become one of the most studied rocks in history, leading the majority of planetary researchers and astrobiologists to ultimately decide it did not contain evidence of life on Mars.
But the real legacy of ALH 84001 lies in the debate that it caused, and the changes that debate engendered. It reinvigorated the field of astrobiology, rekindled NASA’s interest in Mars, and changed how some scientists think about life itself. And depending on who you ask, it’s a debate that isn’t even over yet.
“The question is still open, in my opinion,” Stanford University professor Richard Zare tells Inverse. Zare was one of the original investigators of ALH 84001 and a co-author of a related paper published in the journal Science in 1996.
“It is quite possible that what we found does not indicate a relic of ancient fossil life,” he says. “It’s also possible that it will still prove they are there.”
Already more than 4 billion-years-old, ALH 84001 was likely ejected from Mars during a meteor impact around 3.6 billion years ago. ALH 84001 then fell through space for epochs until finally crashing to Earth in Antarctica some 13,000-years-ago.
A group of prolific meteorite hunters discovered the rock in 1984 and in 1996 Zare and the NASA scientists published their findings in Science. There were the polycyclic aromatic hydrocarbons discovered by Zare, but there were also carbonate globules similar to those left by Earthly bacteria. There wasn’t Martian life exactly, but the scientists argued they had found strong evidence of “biogenic activity” on Mars.
The debate over the findings began unusually, with the details leaked to the press by a Washington D.C. prostitute who had in turn been whispered the information by President Clinton’s adviser Dick Morris. This culminated with Clinton giving a speech before the paper was published in Science.
Science is still being done on ALH 84001. Researchers in Japan recently discovered nitrogen-bearing organic material in the meteorite, adding further evidence that Mars was once a wet, potentially habitable planet.
“Alan Hills is one of the oldest rocks we have from any planetary surface, and so if those globules are not life, or were not made by life or do not track life, then what are they?”
Look like the research and the debate is set to rumble on for a while yet.