Bad news for alien hunters looking for little green things on Mars: the planet is simply too salty for life (or at least ‘most life as we know it’), according to results beamed back from NASA’s Opportunity rover. And it has been for billions of years.

Researchers simulated conditions on the Red Planet based in part on minerals found by Opportunity. They now believe the quantity of minerals dissolved in water would have made life on Mars hard, to say the least.

“This tightens the noose on the possibility of life,” says Andrew Knoll, a member of the rover science team (press release). “Life at the Martian surface would have been very challenging for the last 4 billion years. The best hopes for a story of life on Mars are at environments we haven’t studied yet – older ones, subsurface ones.”

On reading this it instantly springs to mind that there are extreme bacteria on Earth that love salt. Surely something like that could have lived it up in these conditions? Not really – the Red Planet, according to Knoll, is more like the Dead Planet.

“It was really salty – in fact, it was salty enough that only a handful of known terrestrial organisms would have a ghost of a chance of surviving there when conditions were at their best,” says Knoll (BBC).

Speaking at the ongoing AAAS conference, Knoll seems to have been in extreme doom and gloom mode. Even if bacteria did appear, and did survive, a meteor would probably have killed them all off anyway, he says (National Geographic):

“We know that large meteorites can have a devastating effect on life. There would have been a very high probability that the planet would have been hit by sterilizing meteorites.”

Image: The Dead Planet / NASA