New model helps us understand steam worlds better
Scientists have just created a more precise model for "steam worlds"—exoplanets with thick, water vapor atmospheres.
These planets live in wild environments where water isn't just liquid or ice, but can turn into strange states like supercritical fluids and superionic ice.
The new research, published July 24, 2025, in The Astrophysical Journal, helps us get what these worlds are really made of and how they form.
Confirmed 1st steam world
The James Webb Space Telescope (JWST) confirmed the first steam world, GJ 9827 d, back in October 4, 2024. It's about twice Earth's size and sits 100 light-years away, wrapped in a mostly water vapor atmosphere.
Since then, JWST has detected steam in the atmospheres of several sub-Neptunes—making accurate models even more important.
Supporting missions to find life
This new model doesn't just help scientists—it also supports missions like ESA's PLATO, which is set to launch in 2026, which is searching for Earth-sized planets where life might exist.
By understanding steam worlds better, we're one step closer to figuring out what kinds of planets could support life beyond our solar system.