Atmosphere Confirmed on Earth-Like Planet LHS 1140 b, First in Habitable Zone
A research team from the Harvard-Smithsonian Center for Astrophysics has confirmed the presence of an atmosphere on the rocky planet LHS 1140 b, located 48 light-years from Earth. This is the first detection of an atmosphere on a rocky planet in the habitable zone.
Astronomers have confirmed the presence of an atmosphere on a rocky planet located in the habitable zone—a first-of-its-kind achievement. According to a report by Jorge Garay of Wired, a research team from the Harvard-Smithsonian Center for Astrophysics detected a helium spectral signature around the exoplanet LHS 1140 b, which orbits a red dwarf star 48 light-years from Earth.
This result provides the first solid evidence that a rocky planet within the habitable zone can indeed possess an atmosphere. The findings were published in the journal Science.
The presence of an atmosphere is a critical condition for sustaining Earth-like life. On Earth, the atmosphere keeps water in a liquid state, stabilizes temperatures, and reduces harmful cosmic radiation. This discovery is notable as it confirms the existence of a planet meeting such conditions within the Milky Way.
Atmosphere Detected via Helium Leak
LHS 1140 b was discovered in 2017, and these new findings are based on observational data obtained in 2024 and 2025. The team identified a helium spectral signature escaping from the planet 48 light-years away. This revealed not only the presence of an atmosphere but also that the atmosphere has persisted for at least 3 billion years.
The detection method involved first observing the helium spectral signature, then using physical models to reconstruct the mechanism of gas escape from the atmosphere. The validation of this approach is an important result for future research. With more sensitive instruments, it may become possible to fully characterize the atmosphere and investigate whether liquid oceans exist on the surface.
Differences from Earth and Future Challenges
LHS 1140 b being within the habitable zone does not necessarily imply the presence of life or an Earth-like environment. The atmospheric composition estimated from the amount of escaping helium differs significantly from Earth’s. According to the team’s analysis, only the upper layer, where helium escapes, is observable, while heavier gases such as nitrogen, carbon dioxide, and carbon monoxide may exist in the lower layers.
Therefore, a complete understanding of the planet’s atmosphere and an assessment of its habitability will require follow-up studies with more powerful instruments. In a press release, Professor Robin Wordsworth of Harvard University, one of the study’s authors, stated: “Twenty years ago, we weren’t even sure if Earth-like planets existed. Then we learned they are common and even exist in the habitable zone. The next question was which ones actually have atmospheres.”
Editorial Opinion
In the short term, the establishment of this detection method is expected to accelerate its application to other candidate planets. Follow-up observations using existing space telescopes and ground-based facilities are likely to multiply, and similar surveys of multiple Earth-like planets could be conducted within the next few months. The demonstration of the practicality of spectroscopic observation techniques will have a significant impact on observational astronomy practice.
From a long-term perspective, characterizing the atmospheres of exoplanets will move the discussion of habitability toward more concrete terms. The 3-billion-year duration of this atmosphere provides a sufficient timeframe for the emergence of life. However, the possibility of a different atmospheric composition from Earth’s may prompt a rethinking of the very definition of “habitability.”
From the editorial standpoint, this discovery represents only the first step—“confirmation of an Earth-like planet with an atmosphere.” Only a small part of the atmosphere has been observed; reaching evidence of liquid water on the surface or signs of life will require higher-resolution spectroscopic techniques and likely next-generation space telescopes. The next challenge is the detection of biosignature molecules such as oxygen and methane, and the technological roadmap to achieve that is now at stake.
References
- “The Search for Another Earth-Like Planet Just Took a Big Step Forward”, by Jorge Garay — Wired, 2026-07-19T10:00:00.000Z (ARR)
- Source URL: https://www.wired.com/story/search-for-earth-like-planet-step-forward/
Frequently Asked Questions
- Can LHS 1140 b truly be considered an "Earth-like" planet?
- It is similar to Earth in being a rocky planet within the habitable zone and possessing an atmosphere, but its atmospheric composition is likely very different. At this stage, we have only confirmed the existence of a planet with "similar conditions"; the environment cannot be said to be the same as Earth.
- Does this discovery directly lead to the finding of extraterrestrial life?
- No, it is not direct evidence. The presence of an atmosphere is one necessary condition for supporting life, but it alone cannot prove the existence of life. The key will be whether future observations detect biosignatures such as oxygen or methane.
- What technology was used for this detection?
- A technique called spectroscopy was used. By analyzing how gases around the planet absorb or emit light at specific wavelengths (spectral signatures), the composition of the atmosphere is identified. This observation focused specifically on the spectral lines of helium. ## References - [Wired: The Search for Another Earth-Like Planet Just Took a Big Step Forward](https://www.wired.com/story/search-for-earth-like-planet-step-forward/) — Published 2026-07-19 - Science journal paper (Harvard-Smithsonian Center for Astrophysics)
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