--- title: "Scientists Appear to Have Spotted an Unknown Planet in Nearest Star System to Earth" description: "Astronomers using the James Webb Space Telescope have found strong evidence of a mysterious exoplanet in Alpha Centauri." date: "2025-08-07" modified: "2025-08-07" authors: - name: "Frank Landymore" job_title: "Contributing Writer" link: "https://futurism.com/authors/flandymore" url: "https://futurism.com/planet-nearest-star-system" categories: - "Off-World" - "Space" tags: - "Alpha Centauri" - "Exoplanets" - "habitable worlds" - "james webb space telescope" --- # Scientists Appear to Have Spotted an Unknown Planet in Nearest Star System to Earth ![Astronomers using the James Webb Space Telescope have found strong evidence of a mysterious exoplanet in Alpha Centauri.]() *\Image: NASA, ESA, CSA, STScI, R. Hurt (Caltech/IPAC)\* It's not easy to uncover exoplanets, largely lightless objects that either lurk in the dark void of space or are blown out by the light of a nearby star. But astronomers using the James Webb Space Telescope believe they've found a new one — and it's just four light years away. Using the James Webb's Mid-Infrared Instrument, the team found strong clues of a mysterious gas giant in the Alpha Centauri star system, the nearest star system to Earth. Tantalizingly, the suspected world appears to be orbiting in the habitable zone of one of the system's three stars, Alpha Centauri A, which is a remarkably Sun-like star. The detection, as detailed in a pair of [new]() [studies]() accepted for publication in *The Astrophysical Journal Letters*, isn't definitive. But if it's confirmed, the planet would be the nearest exoplanet in the habitable zone of a star that's like our own. "If it's real, it's amazing," Elisabeth Matthews, an astrophysicist at the Max Planck Institute for Astronomy in Germany, [told ]()[*Scientific American*](). "The authors work hard to make a case for why this, frankly, small and faint blob of light is believable, but I think there are still some open questions that need to be answered to really be 100 percent sure." To date, two exoplanets have been confirmed in Alpha Centauri. To look for more, the team used a coronagraphic mask on the Webb's MIRI instrument to block some of the starlight to search for other worlds that might be closely orbiting the stars. They then used computer modeling to rule out other explanations, like a passing asteroid. It was a challenging search. Alpha Centauri A has a companion, Alpha Centauri B, which orbits around the same point, adding to the light that the astronomers needed to look through. They had strong motivation to persevere, however. Alpha Centauri A is a G-type star like our Sun, and its resemblance is uncanny: it's nearly the same weight at 1.1 solar masses, and nearly the same age. Finding a habitable world here would be like finding an interstellar home away from home, to add to the serendipity of it being the closest possible star system to our own. And lo and behold, the team's work revealed infrared emissions that hint at the presence of a familiar-sounding gas giant. "It's something like a Saturn mass, a Jupiter radius, and just like the gas giant planets in our own solar system, if you move them in closer," Charles Beichman, co-lead author of the two papers and an astronomer NASA's Jet Propulsion Laboratory, [told *NPR*](). It might, he added, even have rings. At a suspected temperature range between -40 to -50 degrees Fahrenheit, the candidate is much warmer than the giants of our solar system. Even though that's technically within the habitable range, gas giants are unlikely to harbor life — but it could possess moons that we can't see that *are* habitable. (Saturn's moon [Cassini](), for example, hides a saltwater ocean beneath its icy shell, which scientists believe may be capable of supporting life.) Incredibly, as noted by *NPR* and *SciAm*, this is the scenario imagined in the "Avatar" films, which take place on a fictional moon called Pandora, which — [we are not kidding]() — orbits a gas giant that belongs to Alpha Centauri A. As Sun-like as Alpha Centauri A is, if it does possess a planetary system, it would be starkly different from our own, which is "very quiescent" and "nicely structured," Jason Wang, an astronomer at Northwestern University, told *SciAm.* "There's all the small planets closer in, all the big planets further out, we're almost all on circular orbits." There's also the proximity of another star. By contrast, the candidate gas giant appears to be quite tight to its star, at roughly two astronomical units away, or two times the distance between the Sun and the Earth. Saturn is 9.5 astronomical units away. At so close a distance to the heart of the system, its huge mass could cause chaos to the orbits of its neighbors. "That doesn't bode well for the survival of terrestrial planets," Wang added. We could be getting ahead of ourselves. The astronomers faced a setback when the planet didn't reappear in follow-up Webb observations taken this year. But their hopes were rescued when computer modeling revealed that this could be because at the time those observations were made, its orbit had taken the candidate world too close to the star to see. In any case, hopes are high. The implications could be seismic for our understanding of the nature of planetary systems outside our own. "If confirmed, the potential planet seen in the Webb image of Alpha Centauri A would mark a new milestone for exoplanet imaging efforts," co-lead author Aniket Sanghi, a researcher at Caltech, said in a [statement]() about the work. "Its very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments." **More on exoplanets:** *[James Webb Discovers First-Ever Exoplanet by Taking a Picture of It]()* ## Author At Futurism, my work has often centered on bringing a sense of clarity and insight to complex topics ranging from the regulation of emerging technologies to the esoteric ideologies of Silicon Valley executives, while striving not to lose the poetic sense of awe inspired by often-obscure fields like astrophysics and quantum computing. I broke the story of CNET using AI to produce articles that turned out to be riddled with factual errors and plagiarism — a dam-breaking inflection point, as I've reported, that's inspired copycats and endless discourse while beguiling stakeholders ranging from tech giants to purveyors of spam around the web. My work at Futurism has been cited by publications including CBS News, the Los Angeles Times, Vice, Gizmodo, Engadget, the Verge, and Vanity Fair. I grew up in locales ranging from India to China, and now live in the exotic suburbs of Virginia. In my free time, I'm an avid reader of weird sci-fi literature, an aficionado of East Asian cinema, and, regrettably, a relapsed gamer. Allegedly, I’m working on a debut novel, currently untitled. ### Author social links [Bluesky]()