James Webb telescope reveals secrets of nearby exoplanets.

The James Webb Space Telescope has discovered a mini-Neptune planet, GJ 1214b, around a star 40 light-years away. The planet's atmosphere is made of steam, indicating its past as a possible "water world." The temperature on GJ 1214b shifts dramatically from day to night, indicating that the planet's atmosphere can't be just light hydrogen molecules; instead, there has to be something else like water or methane. Astronomers hope to observe more mini-Neptunes with JWST in the near future to figure out how they are created and how this particular one ended up with so much water.