First atmosphere found on Earth-like planet in habitable zone of distant star

Introduction

In a scientific discovery published in 2026, researchers have detected the first atmosphere surrounding a rocky, Earth-like planet situated within the habitable zone of a distant star. The exoplanet, known as LHS 1140 b, is located 48 light-years from Earth and orbits a red star that is significantly smaller and cooler than the Sun. The findings, published in the journal Science, mark a major milestone in astronomy and planetary science.

Dr. Collin Cherubim, the lead author of the study from Harvard University, described the detection of an atmosphere on a rocky planet within a habitable zone as a significant breakthrough. Joining the research effort was Dr. David Charbonneau, also from Harvard University, who emphasized the importance of the finding to the broader scientific search for life beyond Earth.

Prior to this discovery, no small, rocky exoplanet located in a habitable zone had been confirmed to possess an atmosphere. By confirming that LHS 1140 b has retained an atmosphere, the research provides the strongest evidence to date that planets with conditions similar to Earth could exist outside our solar system.

Background

The search for worlds capable of supporting life has expanded rapidly as observational technology has improved. To date, scientists have discovered over 6,000 exoplanets orbiting distant stars throughout our galaxy. Hundreds of these worlds reside in their stars' habitable zones, often called "Goldilocks zones," where environmental distances allow temperatures suitable for liquid water to exist on a planet's surface.

Despite the high number of overall exoplanet discoveries, worlds that are both rocky and situated in habitable zones remain rare. Out of thousands of confirmed planets, only a few dozen are small and rocky like Earth. Finding atmospheres around these specific worlds has proven to be an exceptional challenge for planetary scientists.

Previous attempts to confirm atmospheres on rocky exoplanets in habitable zones have yielded negative or inconclusive results. A prime example is the TRAPPIST-1 system, which contains seven rocky worlds. NASA's James Webb Space Telescope previously ruled out an Earth-like atmosphere on TRAPPIST-1d, one of the system's rocky planets, while atmospheric data regarding TRAPPIST-1e remains inconclusive.

Astronomers have also investigated larger non-rocky worlds in search of atmospheric chemical signatures. K2-18b, a sub-Neptune exoplanet, was previously monitored for atmospheric dimethyl sulphide, a gas associated with marine life on Earth. However, in 2025, a NASA-led reanalysis of K2-18b established that the previously reported dimethyl sulphide signal was too weak to confirm. The 2025 reanalysis also noted that dimethyl sulphide can form through chemical processes that do not involve biological activity.

Until the latest findings regarding LHS 1140 b, the scientific community had not successfully identified any atmosphere surrounding a small, rocky exoplanet within a habitable zone.

Latest Developments

The new study published in Science details the successful detection of atmospheric gas surrounding LHS 1140 b. Situated 48 light-years away, the exoplanet orbits a red star that is significantly smaller and cooler than our Sun. Its location within its star's Goldilocks zone places it at a distance where liquid water could potentially exist on its surface.

The only gas detected in the atmosphere so far is helium. Researchers believe this helium gas is situated in the upper layer of the planet's atmosphere. While helium alone cannot support life, its presence demonstrates that the planet has managed to retain an atmospheric envelope despite radiation from its parent star.

Scientists involved in the study noted that while helium dominates the upper atmosphere, life-sustaining gases may exist lower in the atmosphere beneath the detected helium layer. Further investigation will be required to analyze the composition of those lower atmospheric levels.

The research team highlighted the broader meaning of the observation for astrobiology. Dr. Collin Cherubim of Harvard University noted that identifying an atmosphere around a rocky world in a habitable zone represents a significant breakthrough. Dr. David Charbonneau of Harvard University reinforced this assessment, emphasizing how critical the finding is to the overarching scientific effort to detect life elsewhere in the universe.

Key Facts

• Planet Name: LHS 1140 b
• Distance from Earth: 48 light-years
• Host Star Type: Red star, significantly smaller and cooler than the Sun
• Planet Type: Small, rocky, Earth-like planet in the habitable zone
• Atmospheric Finding: First detected atmosphere on a small, rocky planet in a habitable zone
• Identified Gas: Helium, likely situated in the upper atmosphere
• Biological Implications: Helium alone cannot support life, but life-sustaining gases may exist lower in the atmosphere
• Key Researchers: Dr. Collin Cherubim (lead author, Harvard University) and Dr. David Charbonneau (Harvard University)
• Publication: Science (published in 2026)
• TRAPPIST-1 Context: NASA's James Webb Space Telescope ruled out an Earth-like atmosphere on TRAPPIST-1d; data on TRAPPIST-1e remains inconclusive
• K2-18b Context: 2025 NASA-led reanalysis showed dimethyl sulphide signal was too weak to confirm and noted the gas can form non-biologically

Conclusion

The identification of an atmosphere on LHS 1140 b provides concrete evidence regarding the physical capabilities of rocky exoplanets. Previously, scientists lacked proof that a small, rocky planet in a star's Goldilocks zone could maintain an atmosphere over time rather than losing it to space environment pressures.

By confirming that LHS 1140 b has retained atmospheric gases, the discovery serves as the strongest evidence to date that planets with conditions similar to Earth could exist outside our solar system. The detection of helium in the upper atmosphere paves the way for future studies aiming to detect potential lower-level atmospheric gases.

Ultimately, this finding moves planetary science a step closer to determining whether life exists on worlds beyond Earth by confirming that rocky, habitable-zone planets can preserve the atmospheres necessary to foster temperate surface environments.