Have they found LIFE ON MARS?

Although it's by no means certain, scientists are slowly accumulating evidence that life once existed on the Red Planet

- ANDREW MAY

Recent headlines hinting at the discovery of life on Mars may sound exciting, but the truth is that the evidence found to date is far from conclusive. It would be great to find unambiguous proof, for example microscopic bacteria or ancient fossils, both of which are plentiful on Earth. Instead, what we see on Mars are tantalising clues that may or may not have a biological origin. The hope is that these will eventually accumulate to the point where Martian life, probably in the distant past, is the most likely explanation. That's the main motivation behind several current and planned missions to the Red Planet, but there was no shortage of speculation even before the advent of space travel.