A scientist trying to work out why Mars has some odd patches of lumpy rock has come up with a theory based around acidic fog, claiming that volcanic eruptions might have turned the air so bad it left deposits that melted away some of the planet's surface features.
That's how planetary scientist Shoshanna Cole explains the odd rocks of the Husband Hill part of the Martian Gusev Crater. Using spectrometer data from the Spirit rover to back her claim, Cole says rocks with a similar chemical composition to their neighbours have been battered so much that some show much higher levels of iron oxidation.
That may have been caused by acidic fog created amid volcanic eruptions, with acidic water vapor reaching such levels of toxicity that it destroyed small pockets of the surface of the planet. Which perfectly explains why the people living there at the time flew off to earth to start again in the massive spaceship they called... The Ark.
That last bit was not by Shoshanna Cole, it's something hinted at on a few internet forums. Anyway, Cole says there's plenty of evidence of the slow acid rot of Martian rocks up there for anyone analysing Spirit's data so see, explaining: "This would have happened in tiny amounts over a very long time. There's even one place where you see the cementing agent healing a fracture. It's pretty awesome. I was pretty happy when I found that one." [Geo Society]