The sky is full of microscopic life, some of which might even trigger rain or snow

By Douglas Fox

Web edition: November 29, 2012

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Clouds are full of living microscopic organisms. Some scientists believe these high-flying germs might sometimes trigger rain or snow.

Credit: Douglas Fox

The alien invaders arrived quietly. Only one man noticed as they drifted down from the sky.

Donald Barber was an astronomer at Norman Lockyer Observatory. Its telescopes sat on a grassy hill surrounded by farmland on the south coast of England. Barber was using the telescopes to measure the light from far-off stars. He captured the starlight in photographs produced on glass plates coated with chemicals, like the film in an old camera. It was only after Barber developed those photographic plates in the summer of 1937 that the first signs of tiny alien invaders emerged.

The astronomer’s discovery was decades ahead of its time. Scientists have only recently shown just how full of life the sky really is. You may see clouds and empty blue when you look up, but millions of pounds of tiny bacteria, fungi and other germs are actually floating up there — sometimes, miles above your head. Germs that cause plant disease can strike from the sky, turning an entire field of lettuce brown all at once. Some scientists believe that germs in the sky may even influence when it rains and snows.

Visit the new Science News for Kids website and read the full story: The high life