"Lurking at the center of our galaxy and in the farthest reaches of space are black holes. Once unseeable and unknowable, these cosmic devourers--sometimes born from the death of stars--swallow even light itself. What exactly is a black hole? And how do we even know they exist? In a kid-friendly, rhyming narration, the elusive astronomical object introduces itself as both a behemoth star-eater and a shy, rarely-spotted phenomena. Physicist Eve M....