NASAさんのインスタグラム写真 - (NASAInstagram)「Yeah, we celebrate Black Friday…. #BlackHoleFriday that is!⁣ ⁣ Let’s go back to basics with some Black Hole 101: A black hole is an astronomical object with a gravitational pull so strong that nothing, not even light, can escape it. A black hole’s “surface,” called its event horizon, defines the boundary where the velocity needed to escape > the speed of light, which is the speed limit of the cosmos. Matter and radiation fall in, but they can’t get out.⁣ ⁣ This image is an artist's concept of a tidal disruption event that happens when a star passes fatally close to a supermassive black hole, which reacts by launching a jet extending hundreds of thousands of light-years into space.⁣ ⁣ Credit: Sophia Dagnello, NRAO/AUI/NSF⁣ ⁣ #BlackFriday #Space #BlackHole #Universe」11月28日 1時55分