On 25 May, it will be five years since Nasa's robotic spacecraft Phoenix touched down in the Martian "arctic". Here, Dr Tom Pike, one of the mission scientists on Phoenix, explains what we've learnt about the Red Planet in that time. I'm tightly sandwiched between missions to Mars. I'm still analysing data from Phoenix, while building hardware for the seismometers launching on InSight. In my spare time, I like to keep an eye on the data coming down from Curiosity. Although workdays and weekends are rather blurred, there are some dates I take great care to remember. Five years ago...
