this report from the New York Times about a “particularly unusual” star about 150 light-years away that’s orbited by three planets: What’s unusual is the inclinations of the outer two planets, HD 3167 c and d. Whereas in our solar system all the planets orbit in the same flat plane around the sun, these two are in polar orbits. That is, they go above and below their star’s poles, rather than around the equator as Earth and the other planets in our system do.
Now scientists have discovered the system is even weirder than they thought. Researchers measured the orbit of the innermost planet, HD 3167 b, for the first time — and it doesn’t match the other two. It instead orbits in the star’s flat plane, like planets in our solar system, and perpendicular to HD 3167 c and d. This star system is the first one known to act like this…
The unusual configuration of HD 3167 highlights just how weird and wonderful other stars and their planets can be. “It puts in perspective again what we think we know about the formation of planetary systems,” said Vincent Bourrier from the University of Geneva in Switzerland, who led the discovery published last month in the journal Astronomy & Astrophysics.
“Planets can evolve in really, really different ways.”