"Studies have shown that microbes can survive the shock levels of being launched into space," said Charles Cockell, a microbiologist at the Open University. "And as more and more organisms are discovered under extreme conditions, it's become more plausible that things could survive in space for the time it takes to go from one planet to another."More about this hypothesis in previous posts Too Many Planets and Hate, Life, the Universe and Everything.
Not long ago, Cockell's claims would have been greeted with scientific derision. But as scientists learn more about Earth and space, the theory, which goes by the grandiose name of "galactic panspermia," seems less far-fetched.
Just because it's fashionable doesn't mean it's correct of course. I think it is though, fashionable or not. The Universe is not a popularity contest, and facts are facts, whether we like them, or even believe them, or not. I could be wrong, I could be right, Time will tell. The important thing is to retain some measure of intellectual honesty, trying as best one can to be objective, while acknowledging and publicising one's inherent subjectivity. Neither being afraid to forthrightly and firmly express an opinion honestly come to, nor to acknowledge contrary evidence.
Readers of this blog will know I do the first; and I honestly try to do the second as well. How far I succeed is a matter for others to decide, not me.