First Rocky Planet with Atmosphere Confirmed in Habitable Zone
Astronomers have confirmed a rocky exoplanet with an atmosphere located within the habitable zone of its star, 48 light-years away.
For the first time, astronomers have confirmed the existence of a rocky planet outside our solar system that not only lies in the habitable zone of its star but also retains an atmosphere. The exoplanet, named LHS 1140 b, is located 48 light-years away and orbits a cool red dwarf. It is composed of rock and is far enough from its host star to potentially sustain liquid water on its surface.
The discovery was made by researchers at the Harvard-Smithsonian Center for Astrophysics, who detected signatures of helium in the planet's atmosphere. Their findings were published this week in the journal Science. The helium signal was observed during 2024 and 2025, and physical models suggest the atmosphere has existed for at least 3 billion years.
While LHS 1140 b is in the habitable zone, this does not guarantee it is Earth-like. The escaping helium indicates an upper atmosphere very different from Earth's, while lower layers may contain heavier gases such as nitrogen, carbon dioxide, or carbon monoxide. The study primarily validates the technique used to detect atmospheres on distant exoplanets.
Moving forward, scientists aim to use more powerful instruments to fully characterize the atmosphere and determine whether the planet has surface oceans or other features compatible with habitability. This marks a significant step in the search for another Earth-like world.
