The Arecibo Observatory in Puerto Rico is seen after Hurricane Maria hit it in September 2017.

A broken cable at Puerto Rico's Arecibo Observatory has torn a gaping 100-foot hole in the dish of one of the largest radio telescopes in the world, taking the instrument offline until repairs can be made.

Arecibo's massive reflector dish, which is built inside a sinkhole in northern Puerto Rico, was damaged when a 3-inch diameter support cable unexpectedly snapped before dawn on Monday, according to the University of Central Florida, which manages the observatory.