A British space expert is convinced that aliens exist.
An expert thinks 'lots' of aliens are out there
Professor John Zarnecki, who is leading Europe's ExoMars mission to put a rover on the Red Planet, has suggested that there is "life everywhere - and probably lots of it".
Professor Zarnecki believes that discovering life elsewhere in the solar system will be all the proof needed to show that it is common everywhere.
He said: "If we find other life in the solar system it almost certainly means life is common everywhere.
"We've discovered over 6,000 planets around other stars which means they're incredibly common. Planets are everywhere which means the number of places where life could develop is just enormous. It's almost infinite.
"So I think we are not alone. There is life elsewhere and probably lots of it."
The scientist added: "It doesn't have to be on Earth-like planets either. It will be the ones that are completely different like in sci-fi movies."