Rain

Scents & Sense-ability

Ever catch that earthy smell after the rain? That’s petrichor — a word derived from the Greek petra (stone) and ichor (the blood of the gods). This signature scent comes from two key ingredients: geosmin, a compound released by soil-dwelling bacteria, and ozone, created when lightning interacts with atmospheric oxygen, contributing a fresh, sharp scent to the mix.

Humans are especially sensitive to geosmin — we’re able to detect it at just 5 parts per trillion (yes, that’s even stronger than a shark’s nose for blood!). Some scientists believe this may be an evolutionary trait: the smell of rain means life-giving water.

The human brain processes smells through the olfactory system, which is directly linked to the limbic system—the area responsible for emotions and memory. This explains why the scent of rain can evoke vivid memories and emotional responses, often associated with comfort and nostalgia.