Astronomers reveal how clouds shape the hidden interiors of the galaxy's most common planets

Article excerpt

Sub-Neptunes are the most common type of planet in our galaxy. Bigger than Earth but smaller than Neptune, these worlds remain deeply mysterious because scientists still do not know what they are made of. What astronomers really want to figure out is their interior composition. They could be rocky planets wrapped in hydrogen-rich atmospheres, or they could be volatile-rich worlds loaded with water or carbon-bearing molecules.