An international team of astronomers led by the Harvard-Smithsonian Center for Astrophysics in the United States has successfully detected an atmosphere surrounding an Earth-like rocky planet orbiting within the habitable zone of another star, marking the first discovery of its kind.
Researchers said the finding represents a major milestone in the search for worlds beyond our solar system that could potentially support life. The results were published in the journal Science.
The habitable zone is the region around a star where temperatures could theoretically allow liquid water to exist on a planet’s surface, provided it has a suitable atmosphere and atmospheric pressure.
Liquid water is considered one of the key ingredients for life as we know it, making planets in this zone among the most promising targets in the search for extraterrestrial life. However, a planet’s presence within the habitable zone does not necessarily mean it is habitable or inhabited; it only indicates that one of the essential conditions for life may be present.
According to the study, the discovery provides the strongest evidence so far that rocky planets located in the habitable zone can retain stable atmospheres for billions of years.
The research focused on the exoplanet LHS 1140 b, located about 48 light-years from Earth and orbiting a red dwarf star within the habitable zone. Scientists detected helium escaping from the upper layers of its atmosphere into space, providing the first direct observational evidence of its kind.
Despite the discovery of thousands of exoplanets over the past decades, confirming the existence of atmospheres around rocky planets — especially those in habitable zones — has remained one of the field’s greatest challenges.
The discovery was based on a theoretical model predicting that the planet would have a helium-rich upper atmosphere gradually escaping into space. The team used a spectrograph on one of the Magellan Observatory telescopes in Chile, taking advantage of two planets transiting their host star on the same night.
Data showed that one of the planets displayed no signs of an atmosphere, while LHS 1140 b revealed clear helium signals, confirming that it has maintained its atmosphere for more than 3 billion years, contrary to some previous predictions.
The results also demonstrated that ground-based telescopes can detect atmospheres on rocky planets by observing gases escaping from them, opening a new approach for studying large numbers of exoplanets without relying entirely on space telescopes.
Researchers described the discovery as a turning point, moving scientists from simply identifying potentially habitable planets to studying their atmospheres and assessing their ability to support life.
The team plans to analyze the planet’s full atmospheric composition and search for other indicators, such as water vapor or oceans, while applying the same model to identify other rocky planets that may possess stable atmospheres.
Researchers said the finding represents a major milestone in the search for worlds beyond our solar system that could potentially support life. The results were published in the journal Science.
The habitable zone is the region around a star where temperatures could theoretically allow liquid water to exist on a planet’s surface, provided it has a suitable atmosphere and atmospheric pressure.
Liquid water is considered one of the key ingredients for life as we know it, making planets in this zone among the most promising targets in the search for extraterrestrial life. However, a planet’s presence within the habitable zone does not necessarily mean it is habitable or inhabited; it only indicates that one of the essential conditions for life may be present.
According to the study, the discovery provides the strongest evidence so far that rocky planets located in the habitable zone can retain stable atmospheres for billions of years.
The research focused on the exoplanet LHS 1140 b, located about 48 light-years from Earth and orbiting a red dwarf star within the habitable zone. Scientists detected helium escaping from the upper layers of its atmosphere into space, providing the first direct observational evidence of its kind.
Despite the discovery of thousands of exoplanets over the past decades, confirming the existence of atmospheres around rocky planets — especially those in habitable zones — has remained one of the field’s greatest challenges.
The discovery was based on a theoretical model predicting that the planet would have a helium-rich upper atmosphere gradually escaping into space. The team used a spectrograph on one of the Magellan Observatory telescopes in Chile, taking advantage of two planets transiting their host star on the same night.
Data showed that one of the planets displayed no signs of an atmosphere, while LHS 1140 b revealed clear helium signals, confirming that it has maintained its atmosphere for more than 3 billion years, contrary to some previous predictions.
The results also demonstrated that ground-based telescopes can detect atmospheres on rocky planets by observing gases escaping from them, opening a new approach for studying large numbers of exoplanets without relying entirely on space telescopes.
Researchers described the discovery as a turning point, moving scientists from simply identifying potentially habitable planets to studying their atmospheres and assessing their ability to support life.
The team plans to analyze the planet’s full atmospheric composition and search for other indicators, such as water vapor or oceans, while applying the same model to identify other rocky planets that may possess stable atmospheres.
