Astronomers Detect Atmosphere on 48-Light-Year Rocky Planet in Habitable Zone
Updated
Updated · Livescience.com · Jul 19
Astronomers Detect Atmosphere on 48-Light-Year Rocky Planet in Habitable Zone
3 articles · Updated · Livescience.com · Jul 19
Summary
LHS 1140 b — a super-Earth about 48 light-years away — is the first rocky exoplanet in a habitable zone with detected evidence of an atmosphere, according to a July 16 Science study.
Using the Magellan Clay Telescope in Chile, researchers identified helium escaping from the planet during a transit, a signal they say reveals a thin upper atmosphere that had been difficult to detect directly.
A September 2024 observation strengthened the case: LHS 1140 b showed a clear helium signature, while nearby planet LHS 1140 c — which transited less than 40 minutes apart — showed none.
That contrast suggests LHS 1140 c likely lost its atmosphere, while LHS 1140 b, at 5.6 times Earth's mass and receiving less than half Earth's sunlight, retained one despite red-dwarf radiation over at least 3.1 billion years.
The finding does not show the planet is habitable or inhabited, but it gives astronomers a new path to probe whether rocky worlds contain gases such as water vapor, carbon dioxide or oxygen.