ELI5: Explain Like I'm 5

Cosmic bomb (phrase)

A cosmic bomb is a phrase that describes a powerful explosion in outer space, usually caused by a star or other large object collapsing in on itself, or sometimes by two stars crashing into each other. This explosion can be incredibly bright and powerful, much bigger than any explosion we have on Earth. It's called a cosmic bomb because it can release huge amounts of energy like a bomb going off.