That earthy smell you love after rain doesn't come from the rain at all. It comes from bacteria older than the dinosaurs

Few natural experiences are as universally loved as the earthy scent that rises after the first drops of rain hit dry ground.

Petrichor, what most people describe as the smell of fresh rain, but the rain itself has almost no scent.

Instead, what your nose detects is a remarkable chemical called geosmin, produced by soil-dwelling bacteria that have been shaping Earth's ecosystems for hundreds of millions of years.The primary source of geosmin is a group of filamentous bacteria known as Streptomyces.

These microbes thrive in soil, where they help break down dead plants and other organic matter, recycling nutrients back into the environment.

Long before the first dinosaurs appeared around 230 million years ago, the ancestors of these bacteria were already flourishing on Earth.