Moon may have already hosted aliens

The Moon could have housed extraterrestrials. Extraterrestrial life could have made its way to our nearest neighbor after a meteorite explosion, scientists have suggested. With that, the atmosphere could have been a lot livelier than today, ready to support life, if only briefly.

This is according to two planetary researchers who found that the Moon could have conditions to support simple life forms four billion years ago. The same conditions could have happened during a peak of volcanic activity 3.5 billion years ago, they say.

Meanwhile, the moon was spitting large amounts of very hot gas, including water vapor. These gases could have formed in the liquid water on the surface as well as creating an atmosphere that could keep it there.

"If liquid water and a significant atmosphere were present on the moon at first for long periods of time, we think the lunar surface would have been at least temporarily habitable," says astrobiologist Dirk Schulze-Makuch in Washington State University, who wrote the paper with Ian Crawford, a professor of planetary science and astrobiology at the University of London.

It is also believed that the Moon was enveloped in a magnetic field that would have kept any form of life that lived there in the shelter of deadly solar winds. The first evidence of life on Earth dates back to around 3.5 and 3.8 billion years ago, in the form of cyanobacteria. Meanwhile, the solar system was a violent place marked by frequent meteorite impacts – it is possible that a life could have been transported to the moon as a result of one of these explosions, suggest the researchers .

"It looks like the moon was habitable right now," said Schulze-Makuch. "There could have been microbes that thrived in the water pools of the moon until the surface became dry and dead."

Researchers now hope speculation will encourage NASA and other space agencies to undertake a "future aggressive program of lunar exploration."