Atmospheric heating might be the secret to keeping planets spinning
D. Aguilar/Harvard-Smithsonian Center for Astrophysics
There may be more Earthlike environments in the universe than previously thought. Warm, rocky planets that orbit close to their stars might not end up with one side in perpetual daylight as suspected, allowing such planets to sustain an environment hospitable to life.
For the first time, researchers have shown that the gentle tug of a star’s gravity on a relatively thin atmosphere can keep a planet spinning even when other forces threaten to slow it down. While planetary scientists have long suspected that this process keeps Venus slowly turning, the mechanism could also work on a planet without Venus’ massive atmosphere, Jérémy Leconte, an astrophysicist at the University of Toronto, and colleagues report online January 15 in Science.
Most stars in the galaxy are M dwarfs, red stars that are smaller and dimmer than the sun. Because these stars are relatively cool, their