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Astronomers have made their strongest detection yet of an atmosphere surrounding a potentially habitable rocky exoplanet, marking a major milestone in the search for life beyond the Solar System, Space.com reports.
The planet, LHS 1140 b, lies about 48 light-years from Earth and orbits within the habitable zone of its host star, where temperatures could allow liquid water to exist.
Researchers directly detected helium in the planet's atmosphere, making LHS 1140 b the first rocky exoplanet with a confirmed atmosphere located in the habitable zone.
"We have directly detected helium in the atmosphere itself, and this is the first direct detection for any rocky exoplanet," said lead author Colin Cherubim of Harvard University. "The fact that it is also in the habitable zone is incredibly important for astrobiology and the search for life."
Scientists have discovered nearly 6,000 exoplanets since the first confirmed detection more than three decades ago. While several rocky worlds have been found within their stars' habitable zones, none had previously been confirmed to possess an atmosphere.
LHS 1140 b orbits a red dwarf, the most common type of star in the Milky Way. Because red dwarfs frequently emit intense stellar flares capable of stripping away planetary atmospheres, astronomers have long questioned whether rocky planets around them could retain one.
The new findings suggest that at least some rocky worlds orbiting red dwarfs can preserve their atmospheres for billions of years, improving their prospects for long-term habitability.
