text: Corkscrew planets spiral between twin suns | New Scientist
  HELTER skelter! It turns out that in some rare cases, a planet in a binary system could spiral around the axis that connects its two stars.
  As it moves closer to one star, the spirals get closer and closer together as the planet moves more slowly, until it turns and moves back toward the other star. In the middle, it traces wild, fast curves around the axis (Astrophysical Journal, doi.org/4j6).
  "Sandwiched between two stars, only a small slice of the planet would ever experience night"
  While the corkscrew planet is mathematically plausible, it is less clear how such an orbit could come to be through the evolution of a real stellar system. "It's hard to imagine planets forming or being captured in such an orbit," says Sara Seager, an astrophysicist at the Massachusetts Institute of Technology. "But for exoplanets, never say never."