Many, many indignities have been visited upon Pluto, the dwarf planet who enjoys far more affection than almost any other planet in the Solar System. But as bad as Pluto has it, it can rest easy that at least it’s not the gas giant Jupiter judo-slammed right out of the solar system.
Scientists have suspected a planet got thrown from the Sol club for a long time; the orbits of Uranus and Neptune don’t make sense with the planets we have, for example. Mostly, the question was: What happened? How did these orbits change, and why?
Researchers at the University of Toronto believe it was Jupiter who did the deed. As Jupiter moved closer to the sun, its gravity interacted with the other planet, and this hypothetical planet was slingshotted into space. It’s called a planetary ejection, and it’s so common scientists believe there are billions of planets just orbiting Galactic Central Point, with no star to call their own.
How do we know this? Jupiter’s moons! The team looked at the orbit of Callisto and found it was consistent with a “planetary ejection.” The other possible suspect, Saturn, couldn’t have participated due to the orbit of its moon Iapetus. That said, most of this is theoretical; it’s all based on computer modeling and there’s quite a bit of disagreement in astronomic circles about whether this happened, and if it did happen, why the hell Jupiter was moving closer to the Sun in the first place.
Still, it’s a good reminder not to step to Jupiter, or Jupiter will kick your ass right out of the Solar System. Good thing we’re going to colonize Mars instead.