A planet that suffers scorching 475°C (900°F) temperatures beneath a thick acidic atmosphere may be the last place you'd expect alien life in our Solar System.

But one NASA scientist claims that extraterrestrials are most likely hiding on Venus amid conditions that are unbearable for humans. 

The new theory was put forward by Dr Michelle Thaller, a research scientist at the US-based Goddard Space Flight Centre.

She says that 'possible signs of life' have already been seen within the carbon-dioxide filled atmosphere, adding that she was absolutely certain that life exists somewhere. 

'We see possible signs of life in the atmosphere of Venus,' Dr Thaller said in an interview with The Sun.

'I never expected Venus. Venus is now one where we see something in the atmosphere that looks very much like it could be produced by bacteria.'

Venus is often described as 'Earth's twin' due to its similar size and structure.

But their conditions couldn't be further apart, as astronomers believe it would be impossible for humans to exist on Venus.

Positioned 67 million miles from the Sun, Venus is the hottest planet in our solar system, suffering temperatures that can even melt lead.