National Aeronautics andSpace AdministrationSafetyInformationCardwww.nasa.gov
What Should I Know AboutBlack Holes?Black holes are physical objects in space, just likeeverything else we see in the night sky.But they pack so much mass into so small a spacethat not even light can escape their gravity.Radiation ConeBlack HoleAccretion DiskEvent Horizon – The Point of No ReturnKnown black holes fall into two classes: Stellar mass: 5 to tens of times the Sun’s mass Supermassive: 100,000 to billions of times theSun’s mass“Middleweight” black holes may existbetween these classes, but nonehave been found to date.9f794d?
Signs a Black Hole is NearBlack holes can be surrounded by rings of gas anddust called accretion disks. The material in the diskgets hot enough to generate X-rays and other light.You can also find black holes by tracking stars’orbits over many years. This is how scientistslearned there’s a supermassive black hole at thecenter of our galaxy!Credit: ESO/M. Parsa/L. CalçadaKeep an eye out for ripples in space-time calledgravitational waves. They can be created when twoblack holes rotate around each other or when astar orbits close to a black hole.Credit: LIGO/T. PylePlease be aware that black holes could bepresent in any direction in space.
Warning Signs You’re Too Close toa Black HoleRadiation Gravity compresses and heatsdebris in the accretion disk to millions of degrees,producing lots of lethal radiation.Time dilation As you get closer to the blackhole, time appears to be passing faster for distantobjects. Anyone watching you will notice timepassing more slowly for you, but you feel like timeis speeding up for everyone else.Spaghettification As objects approach theevent horizon, they’re horizontally compressed andvertically stretched, like a noodle.Once you enter the event horizon, escaping theblack hole requires traveling faster than light. As thistechnology is currently unavailable, please maintaina safe distance from black holes at all times.
Things Black Holes are NotThey are not wormholes (or Einstein-Rosenbridges), providing shortcuts between differentpoints in space. Once you’re in a black hole, youcan’t leave.Contrary to popular belief, blackholes are not cosmic vacuumcleaners. They don’t suck in allother matter. From far enoughaway, their gravitational effects arejust like those of other objects ofthe same mass.They are not portals to other dimensions oruniverses. Even if you could escape a black hole, itwouldn’t be a very nice form oftransportation due to the side effects.
Interesting Facts About Black HolesStellar-mass black holes canbe created when two neutronstars merge. And two blackholes can merge to make alarger one! We’re not surehow the universe makessupermassive black holes,though.Albert Einstein rejected theidea that black holes mightexist.The closest known black hole,called 1A 0620-00, is 3,000 lightyears away. For comparison, ournearest stellar neighbor is 4.2light-years away.3,000light-yearsThe first time we saw a realimage of a black hole was in2019. That was when the EventHorizon Telescope shared animage of M87*, a supermassiveblack hole 55 million light-yearsaway.If you replaced the Sun with ablack hole of the same mass,nothing would happen! Well,it would be a lot colder, butthe planets would stay inthe same orbits.FS-2019-9-437-GSFC
Black holes are physical objects in space, just like everything else we see in the night sky. But they pack so much mass into so small a space that not even light can escape their gravity. Radiation Cone Black Hole Accretion Disk. Known black holes fall into two classes: • Stellar mass: 5 to tens of times the Sun’s mass • Supermassive: 100,000 to billions of times the Sun’s mass ...