Viruses - lots of them - are falling from the sky

"An astonishing number of viruses are circulating around the Earth's atmosphere -- and falling from it -- according to new research. The study marks the first time scientists have quantified the viruses being swept up from the Earth's surface into the free troposphere, beyond Earth's weather systems but below the stratosphere where jet airplanes fly. The viruses can be carried thousands of kilometers there before being deposited back onto the Earth's surface."

[via Massimo, ScienceDaily]