LP 890-9 c

LP 890-9 c orbits an extremely faint red dwarf star just 106 light-years away, completing a lap every 8.46 days from a distance of only 0.0398 AU—closer to its star than Mercury is to the Sun. Despite this proximity, the planet's equilibrium temperature sits at a mild 272 Kelvin, about the freezing point of water, because its host star emits relatively little energy. With a radius of 1.37 Earth radii and a mass of 25.3 Earth masses, LP 890-9 c is a dense, rocky world—significantly heavier than Earth but only modestly larger, suggesting a potentially thick atmosphere that could retain heat. The habitability score of 87 out of 100 reflects these favorable atmospheric and thermal conditions, though the extreme stellar proximity raises questions about long-term atmospheric retention and radiation exposure over geological timescales. The honest uncertainties: we don't know the planet's actual atmospheric composition or whether tidal locking has occurred, both critical unknowns for real habitability. What makes this world compelling is its recent discovery via transit in 2022 and its position in the habitable zone of an ultra-low-mass star—a test case for whether life can emerge around the galaxy's most abundant stellar type.