An Earthy-Smelling Substance, 1964

How the pungent odor that occurs after a light rain became a well-studied phenomenon

Written byLisa Winter

| 3 min read

Photograph of drought land due to climate change

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ABOVE: Hot, arid conditions are ideal for creating petrichor after a brief rain.
© ISTOCK.COM, PANYA RIAMTHAISONG

After long periods of drought or heat, even a brief rain shower brings a welcome respite while filling the air with a rich, earthy scent. The rain doesn’t actually provide any scent itself; rather, the impact of the drops on rocks and soil splashes an oily, bacteria-made substance into the air, creating that distinctive aroma now known by the name of petrichor.

But while scientists and perfumers have been familiar with this scent since the late 1800s, it wasn’t properly defined until 1964 when Isabel “Joy” Bear and Richard Thomas, chemists at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), published “Nature of Argillaceous Odour” in Nature.

“Argillaceous” is a geological term meaning that something contains or resembles clay, but it didn’t seem to be the best fit, as the duo came to realize ...

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Meet the Author

Lisa Winter
Lisa joined The Scientist in 2017. As social media editor, some of her duties include creating content, managing interactions, and developing strategies for the brand’s social media presence. She also contributes to the News & Opinion section of the website. Lisa holds a degree in Biological Sciences with a concentration in genetics, cell, and developmental biology from Arizona State University and has worked in science communication since 2012.
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