Although the moon is uninhabitable today, we cannot definitively rule out that it has never harbored life in the past, according to a couple of American and British astrobiologists who recently published an article on the subject matter in the journal Astrobiology.
American Dirk Schulze-Makuch, from Washington State University, and his British colleague Ian Crawford, from the University of London, explain that the Earth’s natural satellite has experienced two periods of its evolution during which it could have harbored life.
According to them, the conditions on the Moon’s surface made it possible to harbor simple life forms shortly after its formation 4 billion years ago, and again during a peak of volcanic activity about 3,5 billion years ago.
During these two periods, the core of the Moon spewed large quantities of hot volatile gases, including water vapor, towards its surface.
The researchers explain that this degassing could have formed pools of liquid water on its surface and create a fairly dense atmosphere for several million years.
If liquid water and an atmosphere were present for long periods of time after the formation of the Moon, we think that its surface was at least temporarily habitable, says Dirk Schulze-Makuch of Washington State University.
The scientific duo supports their theory with the results of recent space missions and analyzes of samples of lunar rocks and soils that show that the Moon is not as dry as scientists long thought.
Since 2010, space probes have detected ice-water deposits near the North Pole of the Moon. In addition, ice was detected in several dozen small craters.
There is also strong evidence of the presence of a large amount of water in the lunar mantle, which would have been deposited very early in the formation of the Moon. It is estimated that there may be at least 600 million tons of ice on the moon.
Much like the Earth scenario, life on the moon could have appeared as a result of the impact of a meteorite.
On our planet, the first evidence of life comes from fossilized cyanobacteria dating back from 3.5 to 3.8 billion years ago. Meanwhile, the solar system was dominated by frequent impacts of giant meteorites.
It is possible that meteorites containing simple organisms such as cyanobacteria could have been projected from the surface of the Earth and land on the Moon.