Astronomers Find Rocky Exoplanet Neighbor Potentially Suitable for Life 25 Light-Years Away

Astronomers have identified a new exoplanet, GJ 3378b, located just 25 light-years from Earth, which may be rocky and more hospitable to life than previously thought. Initially discovered in 2024, early measurements suggested the planet's mass was over five times that of Earth, implying it might be a gaseous planet similar to a mini-Neptune. However, recent research from the University of California, Irvine, revised its mass to about 2.3 times Earth's, increasing the likelihood that GJ 3378b is a rocky world.

The planet orbits a small, cool red dwarf star and completes a year in just 21.5 days. Despite its close proximity to its star, GJ 3378b receives roughly 90% of the energy Earth gets from the Sun, placing it within the star's "habitable zone," where liquid water could exist if an atmosphere is present. However, scientists have yet to determine whether the planet has an atmosphere, as red dwarfs often emit strong radiation and stellar winds that can strip atmospheres from nearby planets.

Unlike planets that transit their stars from our viewpoint, GJ 3378b was detected through the gravitational pull it exerts on its star, making atmospheric studies more challenging. No evidence of water, oxygen, or life has been found so far. Still, the discovery highlights a promising nearby target for future investigations into whether Earth is unique in hosting life in the universe.

Astronomer Paul Robertson, who led the study, emphasized the significance of the proximity, noting that while 25 light-years equals 236 trillion kilometers, it is a close neighbor within the Milky Way's vast 100,000 light-year span. This proximity makes GJ 3378b an intriguing candidate for ongoing searches for extraterrestrial life.