Astronomers have discovered a new dwarf planet about 300 miles wide at the very edge of the solar system.

Astronomers have discovered a new dwarf planet about 300 miles wide at the outer edge of the solar system.

The closest it gets to the Sun is 80 AU, or about 7.4 billion miles. More tantalizing, however,

… the findings also suggest the presence of another large planet in the outer reaches of the solar system. When the authors plotted the motion of Sedna, 2012 VP113, and distant Kuiper belt objects, they noticed some odd behaviors which they couldn’t explain — but which a massive, “super-Earth” planet about 250 AU away could. They note that such a dimly lit planet “would be fainter than current all-sky survey detection limits, as would larger and more distant perturbers” (i.e., planets), so it’s certainly possible… but right now it’s little more than a guess. A weird, intriguing guess.