Scientists have developed a new model to understand “steam worlds,” which are planets too hot for liquid water at their surface, but could hold the key to finding life beyond our solar system.
These steam worlds, smaller than Neptune and larger than Earth, are often found near stars closer to the sun, making them too hot to support liquid water. Instead, water vapor fills their atmospheres, creating exotic states that scientists can’t replicate on Earth. The new model considers these different states, including supercritical water and superionic ice, to gain a better understanding of these worlds.
The research team’s goal is to determine the composition and origin of steam worlds. By refining this model, scientists hope to shift their focus from less common exoplanets that may be habitable. “Life can be understood as complexity, and water has a wide range of properties that enable this complexity,” said Artem Aguichine, lead researcher.
The development of this new model comes after the James Webb Space Telescope discovered a steam world, GJ 9827 d, in October 2024. Since then, the telescope has confirmed steam in several sub-Neptune planets, making a precise model crucial for understanding these worlds.
While previous models were developed to study icy moons like Enceladus and Europa, the differences between these bodies and sub-Neptunes are significant. Sub-Neptunes exist closer to their stars, with atmospheres that can be thousands of times denser than those on Earth. This makes it challenging to model their behavior.
The team’s new model will be tested by the European Space Agency’s Planetary Transit and Oscillation (PLATO) telescope, set to launch in 2026. By refining their models, scientists hope to improve their chances of finding life beyond Earth.
“The interiors of planets are natural laboratories for studying conditions that are difficult to reproduce,” said Natalie Batalha, a study team member. “The water worlds are especially exotic in this sense.”
Source: https://www.space.com/astronomy/exoplanets-engulfed-in-steam-are-taking-center-stage-in-the-search-for-life-in-our-galaxy