The solar system’s farthest major planet, Neptune, is only 30 astronomical units from the sun. (An AU is the average Earth-sun distance, 93 million miles.) Beyond that, at 30 to 50 AU, lies the Kuiper Belt and its minor planets, including dwarf planet Pluto. Before discovering 2012 VP113 — soon nicknamed “VP” or “Biden,” after the U.S. vice president — astronomers thought only tiny Sedna occupied the empty stretch beyond 50 AU. Now they know it’s not alone.