There's an entire ecosystem of microbal organisms that live in the clouds, according to recent research.
There is, they say, growing evidence that bacteria, fungal spores, and viruses may spend large amounts of time — even their entire lives — in the air, riding clouds across the planet.
And they don't just inhabit the clouds — they may also be creating them. Certainly many of the clouds' newly discovered inhabitants are exquisitely designed to create the maximum number of ice crystals, the basic building blocks of clouds. Some Darwinian biologists even argue that the bugs may have evolved for this very job.
"The ecology of the atmosphere is one of the last great frontiers of biological exploration on earth," says Bruce Moffett of the University of East London in England. Late this year, he plans to conduct the first systematic bug hunt in the clouds above England.
