Neil Degrasse Tyson mocks AM co-host Ryan Bridge over aliens belief

Renowned astrophysicist Neil Degrasse Tyson has mocked AM co-host Ryan Bridge's comment that aliens managed to save a planet from destruction after its sun turned into a red giant star.

Scientists have discovered a new planet, called Halla, which appears to have miraculously survived the violent death of its star Baekdu.

Tyson, who's in New Zealand for a series of shows, was stunned when asked by Bridge if this was proof of aliens who had somehow managed to save the planet from its destruction.

"I don't mean to laugh," Tyson responded. 

"Every time we hit something in the universe that makes us go 'gee this is a mystery', there's people out there - apparently yourself included - where your first explanation is 'aliens'," Tyson said.

"It's obvious," retorted Bridge as his co-host Laura Tupou struggled to contain her giggles.

"I'm thinking you know I don't mind aliens as an explanation but I'm not going there first," he said. 

Watch the video from AM above.