Answer:
because the smell of rain does not come from the water itself
Step-by-step explanation:
The precise aroma of falling rain differs from place to place, season to season, even from one rainfall to another. The scent of rain has been bottled in India since 1911. It's called "mitti attar," or Earth's perfume, and is made from distilling the essence of monsoon-soaked soil. That scent is different from rain cooling a hot sidewalk in New York City, which is in turn distinct from the drops falling on sand, in a grassy field, a forest, or by the sea. The smell of a storm accompanied by lightning is sightly metallic, for example, as oxygen and nitrogen molecules in the atmosphere combine into nitric oxide, while a gentle rain in the woods is rich and fungal.
Yet the scent of rain, particularly after a long dry spell, is pleasing to all, humans and animals alike, in all the places. And, despite countless variations, it goes by a single name-petrichor.The word petrichor was invented by two Australian scientists who introduced it in a 1964 paper on the Nature of Argillaceous Odor (pdf), an investigation into the scent of moistened clay, rock, and sediment. They combined the Greek word for stone, "petra," and "ichor," which means "the blood of gods", to coin a name for the scent of rain.
The mineralogists posited that the scent released by rain isn't that of water, which itself has no odor, but is actually the aroma of organic compounds accumulated in the atmosphere and on surfaces; these are released when rain falls. The compounds include bacteria called geosmin. These bacteria gives beets their earthy flavor and help make digging up soil in a garden so satisfying and soothing.