Petrichor is Roar’s favorite word.

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It comes from the Greek “petros,” which means stone, and “ichor,” which is the blood that flows through the veins of gods.

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It’s the word for the smell that comes after a rain. You know that smell? The one that’s like the time you fell in love during the spring?

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Or the way it feels to be quiet?

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The smell of the earth, with plants and animals and dirt and rocks and clouds and everything? When it’s the thickest and lushest and fullest?

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That’s petrichor.

Here’s what makes it:

  1. When it’s dry for a little while, plants release oils into the ground1,2.6a

  2. Scientists think these oils stop seeds from growing in tough, dry times36b

  3. Meanwhile, Actinobacteria kick the bucket when it’s dry, releasing something called geosmin46c

  4. When it rains, petrichor and geosmin are released from rocks and dirt, and we can smell it.6d

So it’s all that. Plus stones. Plus the blood that flows through the veins of gods.

By Roar

Check our facts!

1http://www.sciencedirect.com/science/article/pii/0016703766900251

2http://www.publish.csiro.au/?act=view_file&file_id=CH9650915.pdf

3http://www.nature.com/nature/journal/v207/n5004/abs/2071415a0.html

4http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1058374/