Scientists have confirmed that LHS 1140b, a rocky exoplanet 49 light years from Earth, possesses an atmosphere, marking the first such detection on a rocky world within a star's habitable zone. The planet, which has 5.6 times Earth's mass and orbits a red dwarf in the constellation Cetus, was originally discovered in 2017.
Researchers detected helium escaping from the planet's upper atmosphere using the WINERED spectrograph on the Magellan Observatory in Chile, though the signal was observed in 2024 but not in subsequent observations. The findings, published in the journal Science, note that no atmosphere was detected around LHS 1140c, another rocky planet in the same system. NASA's James Webb Space Telescope will be used for further study.
Separately, a study in The Astrophysical Journal led by Paul Robertson of UC Irvine reclassified GJ 3378b, a super-Earth 25 light years away originally discovered in 2024, placing it in its star's habitable zone where it receives roughly 90% of Earth's radiation.