Astronomers Detect Atmosphere on Rocky Planet 48 Light-Years Away, a First in a Habitable Zone
Updated
Updated · SciTechDaily · Jul 25
Astronomers Detect Atmosphere on Rocky Planet 48 Light-Years Away, a First in a Habitable Zone
3 articles · Updated · SciTechDaily · Jul 25
Summary
Helium leaking from LHS 1140 b gave astronomers their clearest evidence yet that a rocky, Earth-like planet in another star’s habitable zone still has an atmosphere.
A theoretical model predicted the signal, and the WINERED spectrograph on the Magellan Clay telescope in Chile detected it during a transit, while a second planet crossing the same star showed no such trace.
The Science study places LHS 1140 b about 48 light-years from Earth and suggests its atmosphere has survived for more than 3 billion years, strengthening its status as a target in the search for habitable worlds.
The result also offers ground-based observatories a new way to probe rocky exoplanets by tracking gases escaping into space, with researchers now aiming to identify the atmosphere’s full chemistry and possible oceans.
Could this escaping helium signal be masking vast, hidden oceans of liquid water on a potentially habitable world 48 light-years away?
How did a rocky super-Earth survive the harsh radiation of a red dwarf to keep its atmosphere for three billion years?
LHS 1140 b’s Atmosphere Confirmed: A New Benchmark for Rocky Exoplanet Habitability Around Quiet Red Dwarfs
Overview
Between 2024 and 2026, astronomers used the James Webb Space Telescope to observe LHS 1140 b, overturning the idea that it was a mini-Neptune. Instead, transmission spectroscopy revealed a flat spectrum, suggesting a rocky super-Earth with a possible nitrogen-rich atmosphere that could support liquid water. Later, ground-based observations detected escaping helium, proving the planet still has an atmosphere, likely replenished from within. However, this helium signal vanished in 2025, showing the atmosphere is variable. These discoveries highlight both the promise and the challenges of studying distant worlds, especially with the limits of current technology and the need for autonomous exploration.