What does it rain on other planets?

Rain or sleet, if you will, is much more common in the Solar System than you might expect. Obviously it does not rain like on Earth, but the material that falls from the skies varies according to the planet. Studies have shown that on Mars it rains carbon dioxide, on Titan it rains methane, on Aphrodite it rains sulfuric acid, while on Poseidon it rains diamonds!

Harvard researchers have found a similarity for all the liquid elements that make up rain in the solar system. All drops, regardless of material, are about the same size.

But why should they be so the same size as they are on such different planets one wonders. The researchers' models showed that drops with a radius of less than 1/10 of a millimeter evaporate before reaching the ground, while those with a radius of more than a few millimeters split into two drops to get closer to the average.

The drops of Jupiter and Saturn have a similar shape and size to the drops of the Earth, while the largest drops on Titan are just twice the size of the Earth. It is not clear where this uniformity comes from, but the team suspects it is related to the density and surface tension of the materials.

Understanding the formation of raindrops on other planets will help scientists understand extraterrestrial atmospheres, especially now that their observation tools are growing. It may take some time for a person to see the rain of another world himself, but it is comforting to think that its form is not much different from the rain of the Earth.