Water on Mars is not news, especially… James Lovelock – who worked for NASA developing techniques for testing planetary atmospheres, and comparing Mars with Venus and Earth – argues that you can tell if life exists on a planet by tasting its skies: if it is being breathed out into, it will be a stable but not-inert mix of gases. Lovelock’s full-on Gaia Theory remains outsider science at best, but his characteristic predictive scepticism, which led to it, gets the official nod when required.