A Wonderleaf question
Why does the air smell different after rain?
a real page from the book
After rain, air smells different because falling drops scrub particles from the air and lift scent chemicals from the ground. Soil bacteria make geosmin, a strong earthy compound; raindrops tap it loose. Plant oils and, during storms, a little ozone can join the smell.
A human nose can notice geosmin in incredibly tiny amounts, which may have helped our ancestors find damp ground and water. The name petrichor is for the whole rainy-earth scent, from ancient Greek words for stone and the fluid of gods.
Wonder words
- geosmin
- ozone
- petrichor
- aerosol
Try it out
Step outside after rain, sniff near pavement, grass, and bare soil, then compare which place smells earthiest.
Read the whole picture book
Watercolour scenes, straight answers, about three minutes cover to cover.
Open the picture bookKeep wondering
- Why do mountains change the weather?
- Why is frost sparkly?
- Why is the sky sometimes gray?
- Why do clouds change shape?
- How do meteorologists predict the weather?
- Why is fog close to the ground?
And the next question?
Ask anything — Wonderleaf writes and illustrates a picture book for it. That's the whole idea.
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