Eleven times wider than Earth. Over 300 times more massive. And a million times more terrifying. Jupiter may look like a beautiful ball of swirling clouds, but on the inside, it is a gaseous inferno.

Jupiter is old. Like 4.5 billion years old. It started as a swirling disk of gas and dust that formed into a pretty big planetary core. With time, Jupiter’s core grew, attracting more and more rock, ...