Artistic representation of LHS 1140b
Researchers have achieved a groundbreaking milestone by detecting an atmosphere on the rocky exoplanet LHS 1140 b, situated within the habitable zone. However, many questions still remain unanswered.
The Discovery of LHS 1140 b
An international research team led by scientists at Harvard University has confirmed the presence of an atmosphere around the exoplanet LHS 1140 b. This rocky body orbits a red dwarf star approximately 48 light-years away in the constellation Cetus. The planet, identified in 2017, has a mass 5.6 times greater than Earth’s and a radius that exceeds our planet’s by 70%.
LHS 1140 b resides in the so-called “habitable zone,” the region around a star where conditions may allow for the existence of liquid water on a planet’s surface. The findings were published in the journal Science.
Helium Escaping into Space
The detection was made using the Warm Infrared Echelle (Winered) spectrograph at the Magellan Clay Telescope in Chile. During a transit event in 2024—when the planet passed in front of its star—researchers observed helium escaping from the upper atmosphere of LHS 1140 b. This atmospheric outgassing confirmed that the planet not only possesses an atmosphere but also actively retains it.
Dr. Collin Cherubim, the study’s lead author and a recent PhD graduate in Earth and Planetary Science from Harvard, stated, “This is the first time anyone has found an atmosphere on a rocky planet in the habitable zone of another star.”
Challenges and Future Investigations
Interestingly, subsequent observations in 2025 did not reproduce the helium signal, prompting Cherubim and his team to reassess the initial data. The varying signal might relate to how the planet’s atmosphere responds to extreme ultraviolet radiation emitted by its star.
Despite the excitement surrounding the discovery, researchers caution that the only gas detected so far is helium. Helium cannot support life, and Dr. Yamila Miguel from the Leiden Observatory in the Netherlands emphasized that the observations pertain to the upper atmosphere rather than the lower layers where life could potentially develop.
A Foundation for Habitability
Cherubim insists that LHS 1140 b possesses all the essential ingredients for a potentially habitable environment: a rocky surface, temperatures that allow for liquid water, and an atmosphere that prevents water from escaping while shielding the surface from harmful radiation. Furthermore, the red dwarf star has a relatively quiet nature, producing rare radiation outbursts.
Robin Wordsworth, a professor of Earth and Planetary Sciences at Harvard, places this discovery in a historical context: “Twenty years ago, astronomers didn’t even know if Earth-like planets existed. It turned out such planets are common, even in habitable zones. The next question was whether any of them could maintain an atmosphere. Now we know at least one has.”
Potential Implications
While the detection of an atmosphere on a rocky planet within the habitable zone is unprecedented, researchers caution against drawing definitive conclusions about the potential for life. The study reveals promising avenues for future exploration, but the existence of more life-supporting gases in deeper atmospheric layers remains uncertain.
Since 1995, over 6,000 exoplanets have been confirmed, with atmospheres found around gas giants and sub-Neptunes. However, evidence for an atmosphere around a rocky planet within the habitable zone marks a significant advance in our understanding of planetary systems beyond our own.
The quest to uncover the mysteries of LHS 1140 b continues, highlighting humanity’s enduring fascination with the cosmos and the search for extraterrestrial life.
