Nasa Mars mission declared dead

Nasa says its Phoenix lander on the surface of Mars has gone silent and is almost certainly dead.

Engineers have not heard from the craft since Sunday 2 November when it made a brief communication with Earth.

Phoenix, which landed on the planet's northern plains in May, had been struggling in the increasing cold and dark of an advancing winter.

The US space agency says it will continue to hail the craft but does not to expect to hear from it again.