GJ 3378 b Emerges as Top Life Candidate 25 Light-Years Away
Updated
Updated · Avi Loeb – Medium · Jul 15
GJ 3378 b Emerges as Top Life Candidate 25 Light-Years Away
2 articles · Updated · Avi Loeb – Medium · Jul 15
Summary
A new reanalysis confirms GJ 3378 b as a rocky exoplanet and elevates it to one of the strongest nearby candidates for life beyond Earth.
The planet has a minimum mass of 2.3 Earths, orbits its red-dwarf star every 21.45 days at 0.096 AU, and receives about 90% of the sunlight Earth gets—placing it in the conservative habitable zone.
That habitability case still hinges on atmosphere: researchers say liquid water is plausible only if GJ 3378 b retained enough air to resist sublimation and survive early stellar flares and winds.
Because the planet does not transit its star, the James Webb Space Telescope cannot probe its atmosphere; direct-imaging missions such as NASA’s planned Habitable Worlds Observatory would be needed for a definitive test.
At 25 light-years, GJ 3378 b is farther than Proxima Centauri b at 4.2 light-years, but the report argues it could be the better life candidate if it still has an atmosphere.
Is GJ 3378 b a true second Earth, or is its violent red dwarf star an insurmountable obstacle to life?
Is a world orbiting a star that will outlive our Sun the ultimate prize in our search for a new home?
Could a 'planetary heartbeat' create a habitable twilight zone on a world with a permanent day and night?
GJ 3378 b: A Top Super-Earth Habitability Candidate Just 25 Light-Years Away
Overview
GJ 3378 b, a nearby super-Earth, was confirmed in 2026 as a top candidate for habitability after astronomers conducted refined measurements and recent observations. These studies revealed that GJ 3378 b has a tighter 21-day orbit, placing it within the habitable zone of its cool red dwarf star. This promising position means the planet could potentially support liquid water, a key ingredient for life. The combination of its super-Earth status and favorable orbit makes GJ 3378 b an exciting focus for future research in the search for life beyond Earth.