Why does the air have a special scent after it rains?

Have you ever noticed that the first rain after a long drought brings a special scent, fresh and earthy? This smell has a romantic name: 'Petrichor'. Actually, this scent mainly comes from two sources. The first is oily substances released by plants and accumulated on the surface of soil and rocks. When raindrops fall, these substances can be dispersed into the air with tiny water droplets. The second is 'Geosmin' produced by microorganisms in the soil. The human sense of smell is very sensitive to it, and can detect that familiar earthy smell even at low concentrations. Interestingly, when raindrops hit porous ground, tiny bubbles are created, and when these bubbles burst, they can release fragrant particles into the air. 💡 Today's little knowledge: The scent after rain is not just the smell of rainwater, but the natural aroma created by plants, microorganisms, and raindrops together!