Black holes, from 1783 to now

Black holes: where gravity is so strong that not even light gets out.

What black holes are, the kinds there are, the giant one at the centre of our galaxy, the first pictures, the ripples in space-time from black holes colliding, the people who worked it all out and the myths. Every fact is linked to its source, and there is a quiz at the end.

Start with the basics Take the quiz

A blurry glowing ring of orange light around a dark centre on a black background, brighter at the bottom — The first picture of a black hole: M87*, revealed in 2019.Picture: EHT Collaboration, CC BY 4.0, via Wikimedia Commons (cropped and resized)

4 millionSuns: Sagittarius A*, our galaxy’s black hole NASA

66 billionSuns: TON 618, the heaviest yet seen NASA

1,500light-years to the nearest known, Gaia BH1 NASA

2019the first picture of a black hole ESO, 2019

The short version

A black hole is a place where gravity is so strong that nothing, not even light, can escape from it. NASA Space Place

Black holes aren’t really holes. They are huge amounts of matter packed into very small spaces. NASA

The edge of a black hole is the event horizon. It isn’t a solid surface like Earth’s: it is a boundary that contains all of the black hole’s matter. NASA

Most of the light we see comes from the accretion disk: gas that settles into a hot, bright, fast-spinning disk and slowly works its way in until it falls through the event horizon. NASA, anatomy

Telescopes don’t see black holes themselves. They see what happens around them: hot gas, orbiting stars and bent light. NASA

Sources don’t always agree on the numbers, such as how far away our own black hole is. Where they differ, we show each figure side by side.

A computer visualisation of a black hole: a black sphere surrounded by a glowing orange disc of gas, with the far side of the disc bent up over the top and under the bottom — A NASA visualisation: gravity bends the light from the far side of the disk up over the top.Picture: NASA's Scientific Visualization Studio - KBR Wyle Services, LLC/Scott Wiessinger, University of Maryland College Park/Barb Mattson, University of Maryland College Park/Francis Reddy, University of Maryland College Park/Jeanette Kazmierczak, Public domain, via Wikimedia Commons (cropped and resized)

The parts of a black hole, from the event horizon out to the jets (our drawing, labelled from NASA’s anatomy page).Drawing: our own, simplified and not to scale