Rogue planet moons may stay warm for billions of years, with hydrogen atmospheres trapping heat and enabling liquid water.
A new study led by researchers at the Max Planck Institute for Extraterrestrial Physics and Giulia Roccetti of the European Space Agency suggests rogue planets may host habitable moons. The team found that thick hydrogen atmospheres can trap tidal heat, keeping surfaces warm enough for liquid water for up to 4.
3 billion years. Unlike CO₂-based models, these atmospheres avoid collapse. Combined with tidal-driven wet–dry cycles and ammonia-rich chemistry, such environments could support early life processes—even without any starlight.“We find that such atmospheres can effectively trap heat via collision-induced absorption of H2, maintaining surface temperatures suitable for liquid water for time-scales of up to 4.3 Gyr, depending on the surface pressure, while not prone to condensation-induced collapse,” said researchers in the study abstract. Rogue moon habitatsAstronomers have identified hundreds of exoplanets drifting through interstellar space, many likely ejected from their parent systems by past gravitational interactions. While these rogue planets are expected to be cold and dark, their moons may follow a different path. During ejection, a moon’s orbit can become highly elongated, generating strong tidal forces as it is repeatedly stretched and compressed by its host planet. Similar to Europa and Enceladus, this process can produce significant internal heat, reports Phys.org. If a moon’s atmosphere allows gases to condense, much of this heat would escape into space. However, in dense, hydrogen-dominated atmospheres, heat retention can increase. Under high pressure, hydrogen molecules absorb infrared radiation through collision-induced absorption, where temporary molecular complexes form during collisions.These complexes enhance heat absorption, comparable to greenhouse gases like carbon dioxide and methane. As a result, internal heat could be trapped efficiently without atmospheric collapse. Researchers say such moons could maintain surface temperatures high enough for liquid water without requiring energy from a nearby star, although detecting and analysing such atmospheres remains challenging.Hidden ocean worldsThe new study suggests that moons orbiting rogue exoplanets could sustain habitable conditions for billions of years—despite the absence of any nearby star. The research highlights the role of dense, hydrogen-rich atmospheres in trapping internal heat.Using advanced simulations, the team modeled how a moon’s orbit and atmosphere evolve after its host planet is ejected into interstellar space. Their approach combined atmospheric temperature calculations with chemical processes such as condensation, alongside updated models of orbital evolution that account for declining tidal heating over time.Rogue planets—many of which have already been detected drifting through space—are thought to have been expelled from their original systems through gravitational interactions. While these planets are expected to be extremely cold, their moons may experience intense tidal heating if their orbits become highly elongated. Similar processes are observed on Europa and Enceladus, where gravitational forces generate internal heat, reports Phys.org.The study finds that thick hydrogen atmospheres, potentially up to 100 times Earth’s surface pressure, can efficiently trap this heat through collision-induced absorption. Under such conditions, temporary molecular interactions enhance infrared absorption, allowing heat to be retained far more effectively than in carbon dioxide–dominated atmospheres, which are prone to collapse.As a result, some of these moons could maintain surface temperatures suitable for liquid water for up to 4.3 billion years. The presence of gases such as methane, ammonia, and water vapor may further stabilize these environments, significantly extending the potential window for habitability.“Wet-dry cycling caused by the strong tides together with the alkalinity of dissolved NH3 could create favourable conditions for RNA polymerisation and thus support the emergence of life,” said the team in the research abstract.
European Space Agency Exomoons Exoplanets Hydrogen Max Planck Institute For Extraterrestrial Physics Moon Space Life
United States Latest News, United States Headlines
Similar News:You can also read news stories similar to this one that we have collected from other news sources.
Astronomers keep finding new moons of Jupiter and SaturnKeith Cooper is a freelance science journalist and editor in the United Kingdom, and has a degree in physics and astrophysics from the University of Manchester.
Read more »
Letters: Deflation is the wrong answer for high pricesAlso: A new name | Wishful thinking | Little light | Land grab | Rogue nation. East Bay Times reader letters to the editor for March 22, 2026.
Read more »
4 Cool Costco Finds That Can Help You Build Your Own Hi-Fi Dolby Atmos SetupAndrew is an independent writer with a deep interest in technology, science, entertainment, and history. He has been writing in one form or another since his crayon days, and has been putting various kinds of tech through their paces since his Discman days.
Read more »
Letters: Deflation is the wrong answer for high pricesAlso: A new name | Wishful thinking | Little light | Land grab | Rogue nation. East Bay Times reader letters to the editor for March 22, 2026.
Read more »
Rogue AI Agent Triggers Emergency at MetaAt Futurism, my work has often centered on bringing a sense of clarity and insight to complex topics ranging from the regulation of emerging technologies to the esoteric ideologies of Silicon Valley executives, while striving not to lose the poetic sense of awe inspired by often-obscure fields like astrophysics and quantum computing.
Read more »
How Big Four firm KPMG is protecting itself from AI agents going rogueBusiness Insider tells the global tech, finance, stock market, media, economy, lifestyle, real estate, AI and innovative stories you want to know.
Read more »