Caves found on Mars could be home to alien life.
Aliens could be living on Mars
Experts have used cutting-edge technology to identify plenty of potential tunnel entrances on the surface of the Red Planet which could signal a breakthrough in the quest to find extraterrestrials.
The caves could act as time capsules by preserving biological evidence and other traces of life that have existed on Mars.
Scientists argue that they could also be used as safe spots for humans as space agencies seek to make the planet habitable for people.
Professor James Baldini, from Durham University, said: "Because of the shelter the caves could provide from storms and radiation, they represent an obvious target for human colonisation."