5 Feb 2018
More Planets Discovered Far Outside Milky Way
Scientists have long been unable to find exoplanets—planets outside the solar system—beyond the confines of the Milky Way. After all, our galaxy is a warped disc about a hundred thousand light-years across and a thousand light-years thick, so it’s incredibly difficult to see beyond that. But now, a new study is saying there could be extragalactic exoplanets.
The study, published February 2 in The Astrophysical Journal Letters, gives the first evidence that more than a trillion exoplanets could exist beyond the Milky Way.
Using information from NASA’s Chandra X-ray Observatory and a planet detection technique called microlensing to study a distant quasar galaxy , scientists at the University of Oklahoma found evidence that there are approximately 2,000 extragalactic planets for every one star beyond the Milky Way. Some of these exoplanets are as (relatively) small as the moon, while others are as massive as Jupiter. Unlike Earth, most of the exoplanets are not tightly bound to stars, so they’re actually wandering through space or loosely orbiting between stars