Ancient Earth Microbes Could Be Trapped Beneath Lava On The Moon

There could be life on the Moon after all - from Earth.

A new study has suggested that ancient life or biological material from the very earliest days of the Earth could have made it to the Moon and been buried, safely, beneath lava on the surface.

And that could be crucial, scientists say - because it could be our only chance to get a first-hand look at how life emerged on Earth in the first place.

Published in the journal Astrobiology, the study says that evidence of early chemical evolution in Earth’s early history (around 4 billion years ago) has been lost down here due to that pesky geological process, plate tectonics. But there are places where it could still be found - if the right sequence of events took place.

Richard Matthewman at Imperial and his colleagues report that microbes from that period could have survived being trapped underneath ancient Lunar lava, after being carried there inside debris from an asteroid impact on Earth.

We already know that fossilised microbes from Earth could have made it to the Moon or other regions of space during the Late Heavy Bombardment, a period in which Earth was subject to intense asteroid impacts.

Until now it was not clear how microbes would survive on the Moon due to the intense solar radiation and cosmic rays experienced on the surface. But if the microbes were buried beneath lava on the Moon and survived they would be relatively well protected from the harsh surface.

Matthewman et al tested this by heating organic compounds up to 700 degrees C in a vacuum, alongside minerals designed to simulate the Lunar surface. What they found suggests that compounds and maybe even cells were able to stand the heat for just long enough to survive intact.

“Potentially, if we found a whole series of lava flows and preserved lunar regolith layers with terrestrial meteorites inside, we could use radiometric dating to find out how old the layers are, and look at the meteorites to try and spot the first appearance of recognizable life,” Matthewman told Motherboard.

It doesn’t mean that finding fossils of ancient Earth microbes will be easy. But it does mean it’s possible - and since the Moon isn’t going anywhere soon, that’s good news for biologists both now, and hundreds of years in the future.