Alien life beyond our solar system could be discovered within the next 40 years, a top British astronomer has said.

According to Lord Martin Rees, the president of the Royal Society of London, developments in astronomy mean that astrophysicists could be able to view images of distant planets outside of our solar system as soon as 2025, and potentially discover whether there is some form of life on them, the Daily Mail reported.

The question of whether earth is alone in supporting living organisms has puzzled scientists, philosophers for centuries.

“We know now that stars are orbited by retinues of planets just as our sun is. We have learned this in just the last decade, essentially,” Rees said.

“Within 10 or 20 years we will be able to image other planets like the earth, orbiting other stars. That will be a really exciting subject to see if there is evidence for [extra-terrestrial] life or not,” Rees was quoted as saying by the paper.

Speaking at a debate on the meaning of life for the launch of Professor Stephen Hawking’s new show Grand Design, he added that finding out more about the “origin of life, the place where it exists, and whether aliens exist, is going to be crucial over the next four decades”.

“There may be some questions that our brains will never understand, in the same way that chimpanzees couldn’t understand quantum theory, that are just beyond human brains,” Rees added.

Last year Lord Rees said it was possible that aliens were “staring us in the face” in a form humans are unable to recognise.

“I suspect there could be life and intelligence out there in forms we can’t conceive,” he added.