Astronomers, backed by institutions like Harvard University, have announced the tentative detection of helium in the atmosphere of LHS 1140 b. This rocky exoplanet orbits a dim red dwarf star approximately 49 light-years from Earth. The finding, published Friday in the journal Science, marks what ABC News described as the first detection of an atmosphere on an Earth-like planet beyond our Solar System. Researchers acknowledge the finding is still tentative, not a definitive proof of a helium-dominated atmosphere, but it aligns with their predictive models.
LHS 1140 b is slightly larger than Earth and carries five times Earth’s mass. Study modeling suggests it could potentially be a water world. The planet resides within its star’s Goldilocks zone, a region where temperatures could support liquid water on a planet’s surface. Atmospheres are considered crucial for life on rocky exoplanets, offering a stable climate, protection from radiation, and the ability to trap water.
Capital's Distant Gaze
Collin Cherubim, who led the study while at Harvard University, stated that this planet represents "the best place currently to look for life outside of our Solar System because it has all the main ingredients that we think are essential for life." He expressed hope that this is "just the first [discovery] of many to come." Cherubim described LHS 1140 b as "mostly rocky," with temperatures suitable for liquid water, and noted its relative proximity. He added that it orbits "a star that's very old and quiet" and has "never been seen to flare ... which are all really good things for habitability." This institutional focus on distant, potentially habitable worlds signals a long-term, speculative frontier for capital, even as terrestrial crises deepen.
The planet was initially discovered in 2017. Scientists had previously utilized the state-backed James Webb Space Telescope to search for chemical signatures around rocky planets, including LHS 1140 b, but those observations yielded inconclusive results. Cherubim and his colleagues instead employed a relatively new technique with ground-based telescopes. They looked directly for the specific fingerprint of helium escaping an atmosphere. Helium can be detected much farther from a planet than other atmospheric gases, simplifying its identification. This technique had primarily been applied to large, gassy planets, as it was assumed smaller planets wouldn't exhibit the same telltale signature.
The Pursuit of New Frontiers
Cherubim noted that "Nobody bothered looking for helium on a rocky, Earth-like planet, especially at Earth-like temperatures as well." He explained that "People thought it would be a waste of time because you wouldn't expect a lot of hydrogen or helium ... because they're such light gases that can evaporate to space over time." His team developed a model of how planetary atmospheres evolve over extended periods, particularly those with high helium levels. LHS 1140 b, he said, had "a relatively high probability of having this helium-dominated atmosphere." Cherubim recounted, "And that target jumped out at me because it's a rocky planet, it's in the habitable zone. It would be crazy if it had a helium-dominated atmosphere." When the team observed it, he confirmed, "Lo and behold, there it was."
Tom Evans-Soma, an astronomer at the University of Newcastle specializing in exoplanets, who was not involved in the research, found the signal convincing and called it "very exciting." He had previously been part of an international team that made the first detection of helium in an alien world's atmosphere, though not a rocky Earth-like one. Evans-Soma pointed out that "All of the rocky planets that had hints of atmospheres detected so far have been much hotter and less hospitable planets." He acknowledged that the signal from LHS 1140 b was detected once and not in a second observation, but clarified this isn't unusual for helium.
Uncertainty and Future Prospects
Evans-Soma elaborated that the modeling by Cherubim's team suggested two possible planetary versions: one with low water content and a thick atmosphere, and another with significantly more water than Earth. He stated, "[The model] seems to favour this water world scenario where you've got a mostly Earth-like rocky composition plus 10 per cent water by mass." He found this prospect "very exciting — to imagine what such a planet might be like, especially in the habitable zone, where that water could be in the liquid form on the surface of the planet." The model also indicated that, alongside a substantial amount of helium, the planet might contain water vapor, carbon dioxide, carbon monoxide, and small quantities of oxygen.
Both Cherubim and Evans-Soma stressed the need for further research to confirm the planet's atmospheric composition. Cherubim reiterated, "It's still a bit tentative." He clarified, "It's not like a smoking gun that it's a helium-dominated atmosphere, but it's consistent with the prediction." He plans to search for helium signatures on other planets within their stars' habitable zones. "I have already been awarded time on the same [telescope] to observe a planet that's like a LHS 1140 b twin," he revealed. "It's a very similar star that it's orbiting, it's a very similar size, it's a little bit smaller." He concluded, "That one I'm really excited about," continuing the institutional drive to map potential new territories for future exploration and resource assessment. This ongoing allocation of resources towards distant celestial bodies underscores the priorities of the dominant economic order.