Mars methane mystery plot thickens

A new sensitive survey of the Red Planet's atmosphere has detected no methane - a gas that on Earth is strongly linked to life. The joint European-Russian Trace Gas Orbiter satellite conducted its search last year between April and August. Its observations contrast sharply with detections made by other missions in 2013. The European Space Agency's project scientist on TGO, Håkan Svedhem, explained the situation to our science correspondent Jonathan Amos.