Astronomers have found the strongest evidence yet of a giant gas planet orbiting Alpha Centauri A, the nearest Sun-like star to our own solar system. Located just four light-years away, the Alpha Centauri triple-star system has long been a prime target in the search for worlds beyond Earth.
The discovery was made using NASA’s James Webb Space Telescope (JWST), which detected possible signs of the planet last year. Follow-up observations initially failed to confirm its existence, raising doubts. Now, a fresh round of Webb observations using its Mid-Infrared Instrument (MIRI) has reignited hopes that the planet is real. The findings have been accepted in two papers in The Astrophysical Journal Letters.
A Close Cosmic Neighbour
“This is in our neighbourhood, astronomically speaking,” said Dr. Carly Howett, associate professor of space instrumentation at the University of Oxford, speaking to the BBC. “It’s around a star that is Sun-like and about the same temperature and brightness. That’s really important if we want to think about habitable worlds.”
ALSO READ: ‘Hand-In-Glove With Terrorists’: India Slams Pakistan Army Chief Asim Munir’s Nuclear Threat, Calls It ‘Regrettable’
If confirmed, this planet would be the closest exoplanet in the habitable zone of a Sun-like star. However, scientists stress that because it is a gas giant, similar to Jupiter, it cannot support life directly.
The Possibility Of Habitable Moons
Despite its lifeless nature, the planet could still be home to moons capable of sustaining life. In our own solar system, Jupiter’s moon Europa and Saturn’s moon Enceladus have subsurface oceans beneath icy crusts, leading scientists to believe that life could exist in such environments. A similar setup around this Alpha Centauri planet could provide ideal conditions for extraterrestrial life.
Researchers are already probing such possibilities closer to home through upcoming missions like NASA’s Europa Clipper and ESA’s JUICE (Jupiter Icy Moons Explorer). Unlike those distant moons, however, this new planet lies much closer to its star, potentially offering warmer conditions for its satellites.
Detecting planets in Alpha Centauri is notoriously difficult due to the brightness and proximity of its stars. “These are incredibly challenging observations to make, even with the world’s most powerful space telescope, because these stars are so bright, close, and move across the sky quickly,” said Charles Beichman of NASA’s Jet Propulsion Laboratory and Caltech’s IPAC astronomy centre, co-first author of the study.