The Science Behind That Fresh Rain Smell : Short Wave Scientists have known for decades that one of the main causes of the smell of fresh rain is geosmin: a chemical compound produced by soil-dwelling bacteria. But why do the bacteria make it in the first place? It was a bacteria-based mystery... until now! Maddie gets some answers from reporter Emily Vaughn, former Short Wave intern.
NPR logo

The Science Behind That Fresh Rain Smell

  • Download
  • <iframe src="https://www.npr.org/player/embed/882521771/882573875" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript
The Science Behind That Fresh Rain Smell

The Science Behind That Fresh Rain Smell

The Science Behind That Fresh Rain Smell

  • Download
  • <iframe src="https://www.npr.org/player/embed/882521771/882573875" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Raindrops hang on a blade of grass, after a heavy rain. Christof Stache/AFP via Getty Images hide caption

toggle caption
Christof Stache/AFP via Getty Images

Raindrops hang on a blade of grass, after a heavy rain.

Christof Stache/AFP via Getty Images

Scientists have known for decades that one of the main causes of the smell of fresh rain is geosmin: a chemical compound produced by soil-dwelling bacteria. But why do the bacteria make it in the first place? It was a bacteria-based mystery... until now! Maddie gets some answers from reporter Emily Vaughn, former Short Wave intern.

In this episode, we hear from Klas Flärdh, a professor of microbiology at Lund University in Sweden; Mahmoud Al-Bassam, a researcher at University of California, San Diego; and Paul Becher, a chemical ecologist and a researcher at the Swedish University of Agricultural Sciences.

You can find their paper in Nature Microbiology here.

Email the show at shortwave@npr.org.

This episode was produced by Rebecca Ramirez, edited by Viet Le, and fact-checked by Berly McCoy and Emily Vaughn herself.