A black hole is an area in space that is so compact and stuffed with matter that its gravity
is extremely strong. Since black holes have such a powerful gravitational pull, they suck
in material-including light-at very high speeds. Black holes don't reflect any light, so
they are completely invisible. If we can't see them, how do we know they exist? As black
holes rapidly pull in surrounding material, the material is heated and emits X-rays that
radiate into space. In this way, black holes have profound effects on the matter
surrounding them. By studying these effects, astronomers are thus able to detect the
presence of black holes.
Match causes with their effects.
Scientists can infer the locations
of black holes.
Black holes are invisible.
Cause
Black holes are compactly stuffed
with matter.
Black holes reflect no light.
Material pulled in by black holes
emits radiation.
Black holes have very strong
gravity.
Effect