How do we know?
↻ One of the pages with a moving picture
Super-fast cameras filmed raindrops hitting the ground.
- Tiny living things in soil, called bacteria, make a chemical called geosmin. It smells earthy.
- When a raindrop lands on dry soil, it traps tiny air bubbles.
- The bubbles shoot up and pop, like the fizz in a soda. Scientists think this spray carries the scent into the air.
- A breeze carries the scent to your nose. Ahh, the smell of rain!
Scientists filmed about 600 raindrop tests with super-fast cameras. They saw drops trap air bubbles that burst out in a fizz of tiny bits.
In 1964, two scientists in Melbourne, Australia, named the smell of rain on dry ground petrichor.
Many creatures notice geosmin. In the woods near Alnarp, Sweden, traps baited with soil bacteria lured tiny six-legged springtails. Camels, flies and people notice it too.
Wow number
400 million+ years: scientists think the smell of geosmin has been around on Earth at least that long.
Myth or fact?
The smell of rain comes from the rainwater itself. Myth. It comes from soil and rocks.
People can smell geosmin better than sharks can smell blood. Fact. Our noses are super sensitive to it.
Think about it
Camels, flies and people all notice geosmin. Why might a thirsty camel care about the smell of wet soil?
Where in the world?
Melbourne, Australia where two scientists named the smell of rain on dry ground in 1964. In the woods near Alnarp, Sweden, traps baited with soil bacteria lured springtails — 37.8136° S, 144.9631° E.
Where these facts come from
Every number on page 38, and who measured it
This page tells us about geosmin, the springtail traps in Sweden, and the shark fact.
Research unearths the science behind the smell of spring — The John Innes Centre, a plant and microbe science institute in England
jic.ac.uk/press-release/research-unearths-the-science-behind-the-smell-of-spring
We checked it on 31 October 2026
The scientists' own report (in the journal Nature Microbiology), which tells us exactly where in Sweden the springtail traps were set.
The University of Warwick in England, which keeps a free copy of the scientists' report
wrap.warwick.ac.uk/id/eprint/135205/1/WRAP-developmentally-regulated-volatiles-geosmin-2-methylisoborneol-attract-soil-arthropod-Streptomyces-bacteria-promoting-spore-dispersal-Song-2020.pdf
We checked it on 31 October 2026
This page tells us how about 600 filmed raindrop tests showed fizzy bubbles.
Rainfall can release aerosols, study finds — MIT News, from the Massachusetts Institute of Technology, a science university
news.mit.edu/2015/rainfall-can-release-aerosols-0114
We checked it on 31 October 2026
This page tells us how two scientists in Melbourne named petrichor in 1964.
The smell of rain: how our scientists invented a new word — CSIRO, Australia's national science agency
csiro.au/en/news/all/articles/2015/march/the-smell-of-rain-how-our-scientists-invented-a-new-word
We checked it on 31 October 2026
This page tells us that camels, flies and people notice geosmin.
How Rain Evolved Its Distinct Scent—and Why Animals and Humans Love It — Smithsonian magazine, from the Smithsonian museums
smithsonianmag.com/smart-news/smell-rain-explained-180974692
We checked it on 31 October 2026
Has this changed?
Why rain smells the way it does is not going to change.
Scientists say they only think the spray carries the scent, so that part of the story may grow.
Words from this page
- bacteria
- Tiny living things, too small to see, found in soil and almost everywhere.
- geosmin
- The earthy-smelling chemical that soil bacteria make.
- petrichor
- The name for the smell of rain on dry ground.
Try it!
Do a sniff test.
1. Sniff a pot of dry soil or a dry patch of ground. 2. Sprinkle on a little water. 3. Sniff again. Then wash your hands.
What happens: the wet soil smells stronger and earthier. That’s the smell of geosmin!
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