"Blood Falls" is both more and less interesting than its name suggests

No, it's not a slasher flick about teenagers who take a sexy trip to the lake only end up macheted.

But yes, it is another story about science!

Microbes caught beneath a glacier without sunlight, carbon or oxygen have survived off the energy that is let off from the chemical reaction of sulfur and iron. (Clever!)

The bacteria must have some way of recycling their energy source. Mikucki suggests that they do so using a unique system, where they reduce sulphate to sulphite (SO32-) instead. The sulphite then reacts with iron (which the glacier scours from the underlying rock), and is oxidised back into sulphate, replenishing the original supply. The bacteria do this with a special enzyme called PAPS, or phosphoadenosine-5'-phosphosulphate-reductase, to give it its fuller, catchier name!

What's all this mean? You guessed it: In response to the question posed 40 years ago by David Bowie, perhaps there is life on Mars.