junglee_iitk writes "Three new species of bacteria, which are not found on earth and highly resistant to ultraviolet radiation, have been discovered in the upper stratosphere by some Indian scientists. These bacteria, which do not match any species on earth, were found in samples collected through a balloon sent up to the stratosphere in April 2005. The payload consisted of a cryosampler containing 16 evacuated and sterilised stainless steel probes. Throughout the flight, the probes remained immersed in the liquid neon to create a 'cryopump effect.' These cylinders after collecting air samples from different heights ranging from 20 to 41 km were parachuted down and safely retrieved, it said."
Here's the Indian Space Research Organisation's press release on the discovery
. Adds an anonymous reader: "This paper in International Journal of Astrobiology [PDF]
speculates how microorganisms reach the stratosphere."