> What's the term used to describe the fresh earthy smell after it rains?And the answer: petrichor. When rain falls on dry soil, a fresh earthy scent called petrichor is producedby bacteria in the dirt. The word comes from two Greek words: one for rock orstone, and another from Greek mythology that describes the fluid that flowsthrough the veins of the gods.Petrichor is the result of more than just rain hitting the earth – it's actuallya form of reaction. When a raindrop lands on a porous surface, air from thepores forms small bubbles, which float to the surface and release aerosols. Suchaerosols carry the scent, as well as bacteria and viruses from the soil.Raindrops that move at a slower rate tend to produce more aerosols, which servesas an explanation for why the petrichor is more common after light rains.The molecule that produces smell, geosmin, is present in most healthy soils andis a bacteria also used to create commercial antibiotics. Human beings areextremely sensitive to it, and while we commonly enjoy the smell, the particulartaste (found in vegetables like beets) is commonly disliked. Scientists continueto puzzle over this phenomenon, but more likely than not we may thank our innatehuman inclination toward nature for the pleasant sensation of musky, rainyearth. Check out the video below to learn more.