Small, dim stars could still support life
NASA/JPL-Caltech

Small, dim stars could still support life

Life may be possible around red dwarfs after all. Researchers had long assumed that the small suns (artist’s conception above), which make up about three out of every four stars in the Milky Way, were too dim to provide enough light to any photosynthetic organisms on planets that orbited them. But new research, which will be published in an upcoming issue of the International Journal of Astrobiology, suggests that—based on calculations of exactly how much visible light would be available—such organisms would get enough light to survive, much like plants in Earth’s Arctic Circle subsist on significantly less light than their counterparts at lower latitudes. Still, this hypothetical alien world would need to orbit pretty close to its red dwarf—about as close as Mercury is to our sun—to get this light, and some scientists have said that this would expose the planet to sterilizing doses of radioactivity. But the team behind the new study also waves away that potential buzzkill, stating that after a few billion years these red dwarfs would be no less radioactive than our sun. If the researchers are right about both of their contentions, the study increases the probability of finding life on other worlds nearly a thousandfold, they say, while placing the nearest world where life could evolve less than 10 light-years away.