That fresh smell after rain has a name, petrichor. It starts building up long before the rain.
Where does it come from?
During dry days, some plants release oils that collect in soil and on rocks. Tiny bacteria in the soil also make a chemical called geosmin. Its name comes from Greek and means earth smell.
How does it reach your nose?
When light rain hits dry ground, it traps tiny bubbles of air. The bubbles pop and throw the smell up into the air.
Why is it so easy to smell?
Our noses are super sensitive to geosmin, so even a tiny trace is easy to smell.
Who is it really for?
But that smell is not meant for us. It calls tiny bugs that eat the bacteria and help them spread.
