Black Holes
Regions of spacetime where gravity is so strong that nothing — not even light — can escape.
7 min readUpdated July 20, 2026
What is a black hole?
A black hole forms when a massive star collapses at the end of its life. Its gravity becomes so intense that a boundary called the event horizon forms; anything crossing it is lost to the outside universe.
Types
Astronomers recognize stellar-mass black holes (a few to tens of solar masses), intermediate-mass black holes, and supermassive black holes, which sit at the center of most galaxies — including our Milky Way.
Observing the invisible
Because light cannot escape, black holes are studied indirectly through their effects on nearby matter and light. In 2019 the Event Horizon Telescope produced the first image of a black hole's shadow.