ROANOKE, Va. (WFXR) — Think you’re a weather buff who knows their stuff? See if you can correctly guess this WFXR Weather Trivia question!

What term describes the earthy scent produced by the rain falling on dry soil?

You may have noticed a distinct odor on rainy days, especially when the ground is dry. This scent has been scientifically studied and first given a name in 1964.

This scent occurs when raindrops hit the ground, causing a molecule called “geosmin” to be released into the air. The human nose is very sensitive to geosmin, which is produced by the bacteria Streptomyces.

The term “petrichor” was first coined by Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) scientists Isabel “Joy” Bear and Richard Thomas. Bear and Thomas used the word “petrichor” to describe how the smell comes from an oil certain plants excrete during periods of dry weather. This oil would then be absorbed by the soil and rocks.

Petrichor comes from the Greek words petros, “stone” and ichor, “the fluid that flows in the veins of the gods.”