“We did not expect to find so many microorganisms in the troposphere, which is considered a difficult environment for life,” said microbiologist Kostas Konstantinidis of the Georgia Institute of Technology. “There seems to be quite a diversity of species.”

Some of the bacteria and other organic material, living up to 6 miles above the surface, are believed to have an effect on the weather.

Researchers studied 42 individual pieces of hail, removing the outer layer and sterilizing them before examining what was inside.

It was found that the hailstones contained several kinds of bacteria that can “seed,” or become the core nucleus that ice, clouds and raindrops form around.

Once water vapor latches on to the germs, the various precipitation types grow larger and larger until they become so heavy they fall to the surface.

Hail is formed as the stones travel up and down several times on violent updrafts and downbursts within storms.

Researchers think that common sea spray catapults organisms from the top of the ocean up into the atmosphere.

But it’s unknown how long these organisms can survive or reproduce in the high-altitude and low-oxygen environments.

“I wouldn’t be surprised if there is active life and growth in clouds, but this is something we cannot say for sure now,” said Konstantinidis.

Photo: Wayne Karberg - Flickr