Do black holes suck up everything around them?

A black hole pulls just like anything else that weighs the same. If a black hole just as heavy took the sun's place, the planets would keep going around it as before. Only things that stray very close get trapped. So black holes aren't cosmic vacuum cleaners.

If black holes are black, how do we find them?

Gas and dust swirling around a black hole form a spinning disk that glows brightly, even in X-rays. Stars near one race around something nobody can see. In the middle of our own galaxy, stars zoom around a dark spot with 4 million times the sun's mass. It's a giant black hole called Sagittarius A star.

What is a black hole?

Zib answers for ages 8–11, then goes 2 steps deeper each time a child asks why.

Zib says

Some very big stars, when they run out of fuel, collapse in on themselves. All that star stuff gets squashed into a tiny space. Packed that tight, its gravity grows so strong that nothing can escape, not even light. With no light coming out, it looks completely black. That's a black hole.

For ages 8–10

Checked against What is a black hole? (NASA Space Place)
Do black holes suck up everything around them?

A black hole pulls just like anything else that weighs the same. If a black hole just as heavy took the sun's place, the planets would keep going around it as before. Only things that stray very close get trapped. So black holes aren't cosmic vacuum cleaners.

For ages 9–11

Checked against Black holes (NASA Science)
If black holes are black, how do we find them?

Gas and dust swirling around a black hole form a spinning disk that glows brightly, even in X-rays. Stars near one race around something nobody can see. In the middle of our own galaxy, stars zoom around a dark spot with 4 million times the sun's mass. It's a giant black hole called Sagittarius A star.

For ages 10–11

Checked against Black holes (NASA Science)