Everything you need to know about where the term came from and how we use it today.

Editor’s note: After we first published this story in 2021, we received reader feedback about the term’s derivation and use in pop culture. We updated the story to reflect those additional details.

The JWST has found evidence of auroras and clouds in the atmosphere of the giant rogue planet SIMP-0136, but the causes must be very different from anything we see within the Solar System. When ...