A pair of just-released statistical studies of the universe suggest numerous habitable planets exist in our Galaxy, with one study suggesting a life-friendly planet within 20 light years of our Solar System. From my Nature article, Small stars host droves of life-friendly worlds, that broke news of this latter study, which used data from NASA’s Kepler telescope
[Harvard University astronomer Courtney] Dressing’s study, done in collaboration with Harvard colleague David Charbonneau, focuses on the occurrence of planets that are Earth-sized — which they define as having a radius between half and twice that of Earth — and orbit so-called M dwarfs. These are cool, low-mass stars that account for about 75% of the stars in our Galaxy. In particular, the team looked for planets within the habitable zone, that is, whose orbits put them at the right distance from the star for water to exist in liquid state on their surfaces.
The Harvard astronomers estimate that 6% of the M dwarfs in Kepler’s field of view harbour Earth-sized planets in the habitable zone. That may not sound like much, notes Dressing, but given the preponderance of M dwarfs in the Galaxy, there should be at least one potentially habitable Earth-sized planet around an M dwarf within 20 light years of the Solar System.
More information about both the studies, the data, and the methods can be found in my Nature article.
My scoop was featured on Knight Science Journalism Tracker:
Cowen, a relentless hunter for details nobody else got, waited another day, for another set of papers beyond the ones on the big picture and that got a press conference. He propels the news forward. His main angle is the potential of M-class (or red) dwarf stars to be particularly fecund places for living worlds.