Why does rain smell so good? © Getty Images

Why does rain smell so good?

A complex fragrance which comes from different factors.

Asked by: Carl Dennis, Cumbria

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The fresh, earthy smell that we associate with rain, known as ‘petrichor’, comes from a variety of sources. During dry conditions, certain plants release oils, which then become airborne under the impact of rain.

Falling raindrops also stir up the soil, propelling a musky-smelling chemical secreted by bacteria, called geosmin, into the air. Finally, lightning can split molecules in the atmosphere to form ozone (O3), which has a chlorine-like tang. Some scientists speculate that the importance of rain to our survival has led us to evolve to enjoy its smell.

Why does the ground smell after it rains? © Getty Images

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