These are the ground rules: You can’t say Earth is your favorite planet. This was the framework my colleagues established in a recent newsroom debate over which of the classical planets is the most awe-inspiring. Picking Earth would be obnoxious. Like saying your spirit animal is a human. Well, fine. I pick Jupiter.
Gargantuan, swirling, violent Jupiter. A planet made from the cloud that formed the moment the sun was born. A gas giant that contains more than twice the material of all the other planets in our solar system combined. Huge enough to house 1,300 Earths, and with a midsection that spans 44,308 miles. (The radius of Earth is 3,961 miles.) Jupiter, where winds blow at several hundred miles an hour constantly—as in, all the time and without letting up. Jupiter, where the average temperature is a frigid 235 degrees below zero, but where it gets hotter than lava at lower and lower cloud layers. Jupiter, which gives off more heat than it gets from the sun. Jupiter, where the raging weather includes a mammoth anti-hurricane that has been churning for something like 400 years.
That epic storm is what you see when you notice the planet’s famed Great Red Spot—a massive high-pressure system, equivalent in size to three of our home planet. But it’s not always red. “It’s kind of orange and it changes color,” said Amy Simon, a planetary scientist at NASA. This is just one of Jupiter’s mysteries. From far away, the planet looks vaguely beige. But its clouds are a kaleidoscope of warm colors—alternately red, orange, pink, and tan, with some blue. That may be the effect of sunlight breaking down chemicals like ammonia, but scientists aren’t sure. “We still don't know what makes the clouds the colors they are,” Simon said. “Another thing we don’t know is: Why the storms last so long.”