A solar-system fairy tale
Once upon a time, two giants roughed up the neighborhood.
There's something wrong with the solar system.
First, theories about how planets form suggest worlds like Jupiter and Saturn should orbit the Sun in circular paths that share the same plane. But the orbits of Jupiter, Saturn, and Uranus are out-of-round by up to 9 percent. And the orbital planes of Saturn, Uranus, and Neptune tilt as much as 2° to that of Jupiter's.