http://news.bbc.co.uk/1/hi/sci/tech/6146292.stmsnip
e was able to see the recent work of Dr Louis which shows that the red rain can replicate at 300C, an essential attribute of a space micro-organism that might have to endure extreme temperatures.
Animation of Planet Earth Image: BBC
Bacteria might survive the journey through space
All this has convinced Professor Wickramasinghe that the red rain is a form of alien life.
"Before I came I had grave doubts as to whether the red rain was really an indication of life coming from space; new life coming from space," he said.
"But on reflection and after talking to Godfrey, I think I would now fairly firmly believe that it did represent an invasion of microbes from space."
Many scientists remain highly sceptical, however, but if Wickramasinghe and Louis are correct it will be the strongest evidence so far that the theory of Panspermia might be true.
It also raises the intriguing possibility that if life first originated on another planet then it must mean all Earth organisms, including humans, evolved from alien life.
Horizon - We Are The Aliens is broadcast on BBC Two on Tuesday 14 November at 2100 GMT
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