Researchers have discovered the presence of significant numbers of living microorganisms–mostly bacteria–in the middle and upper troposphere, the part of the atmosphere four to six miles above the Earth’s surface. In other words, the clouds are filled with germs! Do they fall to Earth when it rains? (NOTE: Subscribers can still listen to this incredible show).
They haven’t yet figured out whether these microorganisms routinely inhabit this portion of the atmosphere or whether they were simply lofted there from the Earth’s surface.