Key facts
- An atmosphere has been detected around the Earth-like planet LHS 1140 b.
- LHS 1140 b orbits within the habitable zone of its star.
- The planet is 48 light-years from Earth.
- Helium is the only gas confirmed in the atmosphere to date.
- The discovery marks the first time an atmosphere has been found on a rocky planet in a star's habitable zone.
Researchers have announced the discovery of the first atmosphere surrounding an Earth-like, rocky planet located within the habitable zone of a distant star. This finding represents a significant step in the search for extraterrestrial life, offering the most compelling evidence to date for the existence of worlds similar to Earth beyond our solar system.
The planet, designated LHS 1140 b, is situated 48 light-years away and orbits a red dwarf star. While over 6,000 exoplanets have been identified, LHS 1140 b is notable for being a small, rocky planet within its star's "Goldilocks zone"—the region where temperatures are suitable for liquid water. This is the first time an atmosphere has been confirmed on such a planet.
Currently, the only confirmed atmospheric gas is helium, likely in the upper atmosphere, which alone would not support life. However, scientists suggest that other, more life-sustaining gases may be present in lower atmospheric layers. Dr. Collin Cherubim of Harvard University described the discovery as "a big deal," emphasizing its historical significance.
Other exoplanets are also under investigation for signs of life. K2-18b, a sub-Neptune, previously showed potential signs of dimethyl sulphide, a gas linked to marine life, but this signal remains unconfirmed. The TRAPPIST-1 system's rocky worlds are also being studied, with the James Webb Space Telescope ruling out an Earth-like atmosphere for TRAPPIST-1d and yielding inconclusive data for TRAPPIST-1e.