An international research team led by Harvard scientists has announced the first-ever detection of an atmosphere on an Earth-like rocky exoplanet, LHS 1140 b, orbiting within its star’s habitable zone, only 48 light-years away.

The researchers behind the historic discovery, which they are calling “a major milestone in the search for life on other planets,” said the detection of an atmosphere on an Earth-like rocky exoplanet offers the strongest evidence to date that worlds with similar compositions and temperatures to Earth that are also capable of supporting life could exist beyond our solar system.

Models Predicted First Earth-like Rocky Habitable Zone Exoplanet Atmosphere

In a statement announcing the detection of an atmosphere around a habitable-zone rocky exoplanet, the discovery was motivated by theoretical predictions suggesting that LHS 1140 b may contain an atmosphere. The planet was even more tantalizing because its orbit around its host red dwarf star allows for liquid water on its surface, a key ingredient for life as we know it.

Although thousands of exoplanets have been confirmed since 1995, including habitable-zone rocky worlds similar in size and composition to Earth, the team notes that determining whether any of these potential Earth analogs maintain an atmosphere. Like water, an atmosphere is considered a likely necessity for life to emerge.

“An atmosphere is essential for a planet to support life as we know it,” explained Collin Cherubim, the lead author of a study detailing the findings, who recently earned his Ph.D. in Earth and Planetary Sciences from Harvard University.

Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering and Professor of Earth and Planetary Sciences at Harvard, said that as recently as twenty years ago, astronomers still didn’t know if other, terrestrial-type planets “even existed.” However, he explained, they quickly found that this type of planet was common, including some orbiting within their star’s habitable zone.

“The next question was whether any of them had managed to keep an atmosphere,” the professor added.

Infrared Observations Confirm Historic First  

Before performing any direct observations, the team used computer models to predict what they might find on LHS 1140 b. As noted, those models predicted an upper atmosphere rich in helium. The models also suggested that the atmospheric helium was slowly escaping into space.

To test the model’s predictions, Cherubim and colleagues gained access to the Warm Infrared Echelle (WINERED) Spectrograph on the Magellan Observatory in Chile. The team noted that this powerful telescope allowed them to observe an alignment of LHS 1140 b and another planet transiting its star “on the same night.”

When analyzing the data, the team found that one of the planets appeared to lack any measurable atmosphere. However, as their models had predicted, helium was actively escaping from LHS 1140 b. The finding confirmed that this rocky exoplanet orbiting within its star’s habitable zone was actively maintaining an atmosphere.

David Charbonneau, the head of the Harvard Department of Astronomy and an astronomer at the Center for Astrophysics | Harvard & Smithsonian, and Cherubim’s co-advisor with Wordsworth, was initially skeptical because the entire concept was based on a mathematical prediction of a phenomenon astronomers had never witnessed directly. However, Professor Charbonneau ended up praising the student’s determination and follow-through, which led to the historic detection.

“Collin analyzed the planets we knew about and predicted that this one would have a helium atmosphere,” Charbonneau said. “Then he organized telescope time, got the data, and the detection was statistically rock solid.”

“Hopefully it’s just the First of Many More Observations to Come”

When discussing the implications of the findings, Cherubim noted that “this is the first time anyone has found an atmosphere on a rocky planet in the habitable zone of another star.” Professor Wordsworth agreed, once again noting that until now, planets in these categories with atmospheres had been purely theoretical.

“Now we know at least one has,” the professor said.

The data also suggest that LHS 1140 b’s atmosphere has likely survived for more than three billion years, roughly three-quarters of Earth’s existence. This durability makes LHS 1140 b an excellent candidate for future exoplanet atmosphere studies.

More broadly, the team said that using ground-based observatories to search for escaping gases, such as the helium detected leaving LHS 1140 b, “may become an important tool for studying atmospheres on rocky exoplanets.” They also note the potential value of atmospheric detection for astrobiologists searching for signs of life in the cosmos.

As for Cherubim, he plans on following up his historic discovery with a more detailed analysis of the planet’s atmospheric composition. He also said he would like to investigate the possible presence of surface oceans or other planetary characteristics typically associated with habitability and life. The entire team also said they would like to use Cherubim’s model to search for similar Earth-like, habitable-zone rocky exoplanets.

“This has been a model validation, and hopefully it’s just the first of many more observations to come,” Cherubim said.

The study, “Helium escaping from the atmosphere of a nearby rocky exoplanet orbiting in a habitable zone,” was published in Science.

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

After a discouraging run of bare, airless rocks, astronomers have finally caught a habitable-zone exoplanet hanging onto its sky.

Using spectral data from the Magellan Clay telescope at Las Campanas Observatory, astronomers detected helium escaping from LHS 1140b, a rocky exoplanet that orbits in the habitable zone of the nearby low-mass star LHS 1140.

The post Potential Atmosphere Detected on Habitable-Zone Exoplanet LHS 1140b appeared first on Sci.News: Breaking Science News.

Researchers have discovered a potentially habitable exoplanet just 25 light-years from Earth—but is its precarious location on the cosmic shore too dangerous to make it a home for extraterrestrial life?

In a recent paper in The Astrophysical Journal, researchers at the University of California, Irvine, revealed their discovery of GJ 3378b, an exoplanet that resides in the habitable zone, sometimes referred to as the “Goldilocks zone,” a distance from the host star ideal for liquid surface water.

The habitable zone is a key focus in the search for extraterrestrial life, as planets any closer would have their atmospheres and surface waters burned off, while those any further from their host star would be completely frozen.

Finding Another Earth

“This one’s exciting,” said lead author Paul Robertson, a UC Irvine assistant professor of astronomy and lead author of the new study. “It’s one of our closest cosmic neighbors. 25 light-years sounds like a long way, but the Milky Way is about 100,000 light-years across, so in that respect it’s our next-door neighbor.”

Robertson led the team in the exoplanet discovery, using the Habitable-zone Planet Finder on the Hobby-Eberly Telescope at McDonald Observatory in Texas, and the NEID Spectrometer on the WIYN Telescope at Kitt Peak National Observatory in Arizona.

GJ 3378b is about twice the size of Earth, making it what astronomers call a “super-Earth” for its increased size. Additionally, this potentially habitable exoplanet likely receives a comparable amount of stellar radiation to our planet.

“This super-Earth gets about 90 percent of the radiation from its host star as Earth gets from its sun, so it’s right in the sweet spot,” said Robertson.

Exoplanet Atmosphere

While GJ 3378b resides within its star’s habitable zone, it does so only barely. This fringe area astronomers refer to as “the cosmic shoreline,” a distance just outside of which the stellar radiation would become so intense that its atmosphere would be ripped away, and any potential surface water along with it.

Straddling this shoreline, researchers are uncertain whether GJ 3378b has an atmosphere or is still a victim of excessive stellar radiation, as its larger size relative to Earth may make it more susceptible.

Our own solar system also offers an excellent example of this: the planet Mars, which researchers suspect once had an Earth-like atmosphere, and potentially even life. However, intense solar radiation bombardment destroyed that atmosphere, taking the surface water with it, leaving a desolate wasteland.

“If you scale the Earth down to the size of an apple, its atmosphere would be about as thick as the skin of the apple,” said Robertson. “That’s just enough to maintain the kinds of surface pressures where you can have liquid water. It’s enough that there’ll be breathable air, and it provides maybe a little bit of protection from the harsh radiation environment of space.”

Extraterrestrial Life on Exoplanets

Although GJ 3377b is relatively close to Earth on a cosmic scale, current equipment cannot determine whether the planet harbors an atmosphere. To do so, advanced future observation platforms will be required, and just such work is on the horizon.

“If a planet in the habitable zone has a proper atmosphere, we can justify further research looking for biosignatures, liquid water, or other signs of life that require both an atmosphere and the right amount of heating from the host star,” said co-author Gogod James, a UC Irvine student in Robertson’s group who worked to characterize the size of GJ 3378b.

NASA plans to take a closer look at these potentially habitable worlds in about two decades with its upcoming Habitable Worlds Observatory (HWO). Launching in the 2020s, HWO will be a large infrared/optical/ultraviolet space telescope designed to confirm whether exoplanets have atmospheres, and then seek biosignatures within those atmospheres, which could indicate the presence of extraterrestrial life.

The paper, “A Revised Mass and Period for the Habitable Zone Super-Earth GJ 3378 b: A Planet Straddling the Cosmic Shoreline,” appeared in The Astrophysical Journal on June 30, 2026.

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.