BULLETIN

Ancient microbes may survive Mars radiation

The discovery could lead to tighter planetary protection

Bacteria could survive Mars’s radiation much longer than previously thought, a new study has found. Past experiments that subjected Deinococcus radiodurans – nicknamed Conan the Bacterium due to its hardiness – to the radiation it would experience just below the Martian surface found it could survive one million years. However, the new experiments froze and dried the bacteria, as would probably be the case on Mars, and buried it 10 metres down. Here it could withstand 280 million years of radiation.

Though the find raises hopes of finding life on Mars, it does mean preventing cross-contamination is even more critical.

“We concluded that terrestrial contamination of Mars would essentially be permanent – over timeframes of thousands of years,” says Brian Hoffman from Northwestern University. “Likewise, if microbes evolved on Mars, they could be capable of surviving until the present day. That means returning Mars samples could contaminate Earth.” www.northwestern.edu