Image via Unsplash/ Reza Shayestehpour.
Earth has raindrops of water, while, on Venus, the rain is made of sulfuric acid. Jupiter rains droplets of helium. Saturn’s moon Titan rains methane. On Neptune and other gas giants, a diamond rain may fall. And, in the case of exoplanet WASP-76b, raindrops are thought to be made of superheated liquid iron. But here’s one thing these different types of raindrops might have in common: their size. A new study – led by Kaitlyn Loftus of Harvard University – was announced on April 5, 2021. It suggests that, on whatever planet or moon rain falls, that particular world’s atmospheric and gravitational constraints keep raindrop sizes within a range that’s common among worlds. Loftus commented:
There’s a fairly small range of stable sizes that these different composition raindrops can have; they’re all fundamentally limited to be around the same maximum size.
For example, on small rocky planets like Earth, Venus or Mars, these scientists said they :
… found raindrops with a radius smaller than about a tenth of a millimeter evaporate before they ever reach the surface, and raindrops larger than several millimeters in radius break up into smaller droplets as they fall.