It’s the rain and the dirt that mix together aromatically to set the mood for the day. The most refreshing of fragrances, the most ambrosial smell that brings us closer to emotions and sentiments as soft as the wet mud is one of the most cherished mysticism of nature. Now, the physics and logic, which in laymen terms would be some divine alchemy, is right there to back the romanticism up with science. How do we smell it? There is a common substance in the forests areas known as geosmin, produced by a bacteria called actinomycetes that swell the soil. Now, when the bacteria creates spores, the compound is secreted which are bounced into the air with force of the falling rain. The spores containing geosmin get splashed and spread in the air where they remain as we walk into them and to be received by the enticing fragrance.

Why is it so attractive?

If you have noticed, the smell of the rain washed earth is best with the first shower after a dry spell. It’s because that is when the highest amount of geosmin spores is deposited in the world around you.

However, many of us can detect the smell even if the concentration of geosmin in air is as low as five percent per trillion. The human senses are that sensitive to the smell.

Why do we love it?

Some studies puts it as a genetically inherited association of happiness and hope with rain over generations, since prehistoric times. The rains have always meant the bringer of the most primitive and the bare basic pleasures life like food, flowers, the flora and the fauna.

We are, apparently, hard wired to be automatically elated to the smell brought down by the rains.