Understanding how planets can and do orbit is key to understanding how solar systems form and evolve. We’re pretty sure planets form in a nice disk orbiting the equator of their host star, and after that, all things seem possible. 

The majority of studied solar systems have worlds that orbit, like ours, mostly around the equator all in the same direction the star is rotating. BUT there are weirdo planets out there not doing that, and it was originally thought the weirdo planets would have a random distribution. This is consistent with them getting out of place through collisions or being stolen from other systems. The thing is, a new paper published in The Astrophysical Journal led by Simon Albrecht, finds these out-of-alignment systems are preferentially tilted 90 degrees (ish) to their home star’s rotation. Why? No idea. “The universe likes to mess with us” is as good a reason as any.

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Peculiar Planets Prefer Perpendicular Paths (Eos)

“A Preponderance of Perpendicular Planets,” Simon H. Albrecht et al., 2021 July 16, The Astrophysical Journal Letters