How Moon could have been a cradle for life

Satellite had atmosphere and may have supported organisms brought by a meteorite, say scientists

WHEN Neil Armstrong set foot on the Moon’s surface in July 1969, it was not only a giant leap for mankind, but also the first time the satellite had ever hosted life.

The lunar world was thought to be a “dead rock”, lacking the volcanic activity needed to create an atmosphere and without sufficient gravity to trap the molecules needed for microbes to evolve. But now, scientists from Birkbeck, University of London, and Washington State University have found that conditions on the lunar surface could have supported simple lifeforms around four billion years ago – roughly the same time that life was getting started on Earth.

During this period, the Moon was spewing out large quantities of superheated gases, including water vapour, from its interior. Not only did it create an atmosphere, but the escaping steam could have condensed into pools of liquid water on the Moon’s surface, becoming a perfect breeding ground for microorganisms.

Dr Dirk Schulze-makuch, an astrobiologist at Washington State University, said: “It looks very much like the Moon was habitable at this time. There could have actually been microbes thriving in water pools on the Moon until the surface became dry and dead.

“If liquid water and a significant atmosphere were present on the early Moon for long periods of time, we think the lunar surface would have been at least transiently habitable.”

The findings are based on data from recent space missions and analyses of rock and soil samples that show the Moon is not as dry as once thought.

In 2009 and 2010, an international team of scientists discovered hundreds of millions of metric tons of water ice on the Moon. Additionally, there is strong evidence of a large amount of water in the lunar mantle that is thought to have been deposited very early on in the Moon’s formation.

It is thought the Moon was formed 4.5 billion years ago when a large planet, which scientists have named Theia, crashed into Earth, creating a huge debris disc that eventually swirled together to form the satellite.

While today’s Moon is silent and sterile, around four billion years ago it would have been fiery and active following its dramatic birth. Lava flows have also been dated to between 3.8 and 3.1 billion years ago showing it took more than a billion years to cool down.

Although the conditions were present for life to evolve on the Moon as it did on Earth, researchers think it is more likely that organisms were brought by a meteorite.

Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London, said: “We know we have lunar meteorites on the Earth, so it may well be that a chunk of Earth carried life to the Moon.

“If we can drill down and find evidence of early life it could show us what life was like on the early Earth.

“I am sure the Moon is completely dead now, but it once would have been very active and we have evidence from the Apollo missions of lava flows dating back billions of years.”

The research was published in the journal Astrobiology.

Life might have flourished on the Moon some time ago, scientists now say. The time they specify is four billion years, just when primitive life forms were pottering around the ocean floor on Earth, warming their pseudopodia at volcanic chimneys. If there was life on the Moon, has it all gone? We used to think it very modern to conceive of the Moon as utterly sterile, but then we also thought there was no water on the Moon. The scientists tell us now that there is six billion tons, give or take. Before the idea of sterility took over, everyone knew the Man in the Moon lived there with his dog and a bundle of thorns. Shakespeare made a rude mechanical play the part in A Midsummer Night’s Dream. What would be more surprising to find in a Moon crater now – extremophile microbes or the Man and his dog?