Exoplanet LHS 1140c Sheds Helium as It Orbits Its Star Every 4 Days
Updated
Updated · Ars Technica · Jul 16
Exoplanet LHS 1140c Sheds Helium as It Orbits Its Star Every 4 Days
1 articles · Updated · Ars Technica · Jul 16
Summary
A Nature study detected helium escaping from LHS 1140c, offering direct evidence that the exoplanet is losing part of its atmosphere.
About 50 light-years away, LHS 1140c circles the red dwarf LHS 1140a in just under four days and absorbs roughly five times the radiation Earth gets from the Sun, conditions that can heat and expand an atmosphere.
The finding matters because hydrogen and helium are thought to dominate planets' original atmospheres, but both can leak into space over billions of years as radiation, gravity and chemistry reshape them.
That process is believed to have left Venus, Earth and Mars with secondary atmospheres, making LHS 1140c a useful case for testing how close-in exoplanets evolve.
If one planet is losing its atmosphere, could its sister world be the system's true cradle for life?
Some planets may 'reinflate' their atmospheres from within. Is this the secret to forming a habitable world?
This exoplanet is bleeding helium into space. Are we watching the birth of a new rocky world?
LHS 1140b’s Persistent Atmosphere: First Detection of a Rocky Exoplanet with a Stable Envelope in the Habitable Zone
Overview
In 2024, scientists led by Jason Dittmann made a groundbreaking discovery by detecting a helium-rich atmosphere around LHS 1140b, marking it as the first confirmed rocky exoplanet in a habitable zone with an atmosphere. This finding provides crucial evidence that such planets can retain atmospheres, sparking intense scientific interest and opening new research directions. The presence of helium raises important questions about whether LHS 1140b’s atmosphere is temporary or stable. Future studies, especially with the James Webb Space Telescope, aim to determine the atmosphere’s persistence, profoundly impacting the search for life beyond our solar system.