(Encore episode.) Scientists have known for decades that one of the main causes of the smell of fresh rain is geosmin: a chemical compound produced by soil-dwelling bacteria. But why do the bacteria make it in the first place? Reporter Emily Vaughn answers this bacteria-based mystery.Read the paper
on which this episode was based.
Other scent mysteries driving your nose wild? Email the show at email@example.com
and we might track down the answer.