They found a diatom in the stratosphere, and know of no mechanism whereby a diatom could be blown so high. Well, okay, there's volcanoes, but there haven't been any in the last three years so that's right out. Therefore it comes from outer space, possibly from a comet, and we can feel reasonably confident this is happening all the time and life originated elsewhere. Yes, that does seem to be the only other possibility. Can't imagine any other way it got there.
The story becomes clearer only at the end of the article.
"It isn't a real science journal at all, but is the ginned-up website of a small group of crank academics obsessed with the idea of [Fred] Hoyle and [Chandra] Wickramasinghe that life originated in outer space and simply rained down on Earth," P.Z. Myers, a biologist at the University of Minnesota, Morris, wrote on his popular science blog Pharyngula.
Wickramasinghe is a co-author of the new stratospheric diatom paper, a fact that could color its reception in the wider scientific community.
"I don't have ANY expertise in this area," Rosie Redfield, a microbiologist at the University of British Columbia, told SPACE.com via email. Redfield was among the outspoken critics of the Journal of Cosmology's 2011 meteorite announcement. "But neither the Journal of Cosmology nor Dr. Wickramasinghe have any scientific credibility, and one fragment of a diatom frustule is hardly significant evidence."Well, send a jug of the best claret round to P.Z. Myers and Ms. Redfield, then. The former is a prominent atheist blogger, according to my scanty research, but he deserves the jug nonetheless.