'Caves have been found on Mars – and they could be home to alien life, scientists said on Sunday.
The entrances to seven possible caverns on the slopes of a 16km-high (10mile) Martian volcano called Arsia Mons were spotted by Nasa satellites.
The find will fuel suggestions that life may exist in 'underground habitats' on the Red Planet. The caves could one day become shelters for astronauts, scientists at the US space agency said.
