Stephen Hawking thinks we're playing a dangerous game by trying to contact aliens.

The physicist believes that if aliens discovered Earth, they are likely to want to conquer and colonise our planet.

'If aliens visit us, the outcome could be much like when Columbus landed in America, which didn't turn out well for the Native Americans,' he said in a recent interview.

But co-founder and former director of the Seti Institute, Jill Tarter, doesn't think this will be the case.

She argues that any aliens who have managed to travel across the universe will be sophisticated enough to be friendly and peaceful.

'The idea of a civilisation which has managed to survive far longer than we have...and the fact that that technology remains an aggressive one, to me, doesn't make sense,' Tarter told Business Insider.

Tarter is not stupid, just dangerously naive. To read more and view the video, click here.