Proof there’s life of Mars could appear in 20 years, though aliens could find us first, an expert has said.

According to astrophysicist Sarah Cruddas, decades of exploration of the Red Planet by unmanned probes could pay off.

Scientists have revealed that organic molecules found on Mars are "consistent with early life", a tantalising clue in the hunt for alien life in our Solar System.

Nasa believes ancient Mars was similar to Earth and was once much "wetter and warmer".

“When you look at the numbers, it’s likely that we’re not alone in the universe,” Cruddas told the Daily Star on Sunday.

“We know Mars has been warmer and wetter, so has the conditions for microbial life, which is single cell organisms. We just haven’t been able to prove it yet.

“Whether it is microbial life or something beyond explanation is yet to be seen.

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