Mars is about to be invaded by three successive spacecraft carrying sophisticated scientific instruments, six-wheeled robotic “rovers” and two sundials from Seattle. The planned landing on Christmas Day of Britain’s Beagle 2 will be followed by two NASA probes, Spirit and Opportunity, which will land on different days in January. The general purpose of the missions is to find evidence of life, or past life. What does a sundial have to do with this and why on Earth would it come from soggy, cloudy Seattle?