Event horizon
A boundary around a black hole within which no event can affect an outside observer, constituting the black hole's point of no return.
Timeline (last 90 days)
For stellar-mass black holes, the region where tidal forces are strong enough to tear objects apart lies far outside the event horizon; for supermassive black holes, tidal forces near the event horizon are instead relatively small, so an astronaut might safely cross the horizon first and then be torn apart near the singularity.
The event horizon is the boundary of a black hole; once crossed, no object (including light) can escape.
From an external observer's perspective, an object falling into a black hole appears to freeze forever near the event horizon and gradually turn red and dim, a phenomenon known as gravitational redshift.
All Facts (3)
For stellar-mass black holes, the region where tidal forces are strong enough to tear objects apart lies far outside the event horizon; for supermassive black holes, tidal forces near the event horizon are instead relatively small, so an astronaut might safely cross the horizon first and then be torn apart near the singularity.
50%UnverifiedThe event horizon is the boundary of a black hole; once crossed, no object (including light) can escape.
50%UnverifiedFrom an external observer's perspective, an object falling into a black hole appears to freeze forever near the event horizon and gradually turn red and dim, a phenomenon known as gravitational redshift.
50%