5 mind-bending black hole facts that will change how you see the universe

A black hole's gravity at the event horizon is so strong that nothing, not even light, can escape

Image Credit: NASA 

Black holes are invisible because no light escapes them, but space telescopes can detect them by observing how nearby stars behave differently

Image Credit: NASA, Event Horizon Telescope Collaboration 

Sagittarius A, the supermassive black hole at the Milky Way's center, has the mass of 4 million suns and could fit in a ball holding a few million Earths

Image Credit: NASA

If the Sun were replaced by a black hole of equal mass, it would get much colder, but the planets would remain in their orbits

Image Credit: NASA

The heaviest known black hole, TON 618, is 66 billion times the Sun’s mass, while the lightest is just 3.8 times the Sun’s mass and orbits a star

Image Credit: NASA, ESA, Joseph Olmsted (STScI)