NASA’s Goddard Space Flight Center
Astronomers just measured the mass of a free-floating planet without a star for the first time
Topics: Astronomy, Astrophysics, Exoplanets, NASA
When we imagine a planet, we think of one like ours, orbiting a star. But some have a far lonelier existence, drifting through interstellar space without a sun to call their own. Known as “rogue” or “free-floating” planets, these worlds are often challenging to study. With no known star and no orbit from which to estimate their size, they’ve generally flown under the radar—until now.
In a new study published in Science on Thursday, scientists show how they measured the mass of one such rogue planet for the first time—a breakthrough that could enable further studies of these strange, lonely worlds.
Instead of looking at the planet’s orbit, the research team, led by Subo Dong of Peking University, instead analyzed how the planet’s gravity bent the light from a distant star, in a so-called microlensing event, from two separate vantage points: Earth and the now-retired Gaia space observatory.
Scientists Just Clocked a ‘Rogue’ Planet the Size of Saturn, By Jackie Flynn Mogensen, edited by Claire Cameron, Scientific American
Physics and Nano 