Tiny Microbes Could Survive Space and Contaminate Mars: Dangers of Life for the Red Planet

We shouldn't worry too much about invaders from space. Instead, we should worry about our own invasiveness on other planets. Scientists are concerned that micro-organisms from Earth could potentially contaminate and invade Mars, surviving even under the harsh environmental conditions.

It's difficult to keep a spacecraft completely pristine, and it wouldn't be all that unusual to find that organisms hitched a ride and then contaminated other celestial bodies. This would make it difficult for scientists to determine whether life was already located on a planet, or if it was brought by spacecraft. Not only that, but current policies may not be enough to prevent this contamination.

"If you are able to reduce the numbers to acceptable levels, a proxy for cleanliness, the assumption is that the life forms will not survive under harsh space conditions, "said Kasthuri J. Venkateswaran, one of the researchers, in a news release. Unfortunately, though, this particular assumption may not hold up. Some microbes are hardier than expected and could survive interplanetary flights.

In fact, scientists have found that spore-forming bacteria could potentially survive, especially since spores can withstand certain sterilization procedures. In a recent experiment, Bacillus pumilus SAFR-032 spores were exposed for 18 months on the European Technology Exposure Facility (EuTEF) outside the space station.

"After testing exposure to the simulated Mars environment, we wanted to see what would happen in real space, and EuTEF gave us the chance," said Venkateswaran in a news release. "To our surprise, some of the spores survived for 18 months."

The findings reveal how robust microbes can be. Not only that, but they reveal the importance of making sure that spacecraft are sterilized. If proper precautions aren't met, we could contaminate other planets with microbes, which could hinder scientists' search for life on planets other than Earth.

The findings are published in Astrobiology Journal.