Here on Earth, our days are predictable, with sunrise following sunset each day at regular intervals. The Sun rises in the east and sets in the west. But what if that wasn’t the case? What if the Sun set in the west one day and in the north the next?
Inhabitants of two of Pluto’s moons—Nix or Hydra—would not know when each day would begin and from which direction the Sun would rise. This is because, like two cosmic footballs, these moons are wobbling erratically as they travel through space. “Living on Nix, you literally would not know if the Sun was coming up tomorrow,” said Mark Showalter of the SETI Institute and co-author of a new study.
The Pluto system is unique in that it contains the only binary planet system in our solar system. Pluto and its largest moon Charon are what scientists refer to as a double-dwarf system. Pluto is currently classified as a dwarf planet; while Charon is technically labeled a moon, both bodies orbit the same point in space—a point that isn’t within the circumference of either body.
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