By Ron Cowen
When it comes to the biggest bodies in the solar system beyond Neptune, Pluto tops the list. Charon, Pluto’s moon, has always been designated the runner-up.
Astronomers now have for the first time found an object that’s slightly bigger than Charon. It’s an icy body in the Kuiper belt, a reservoir of comets in the outer solar system.
Dubbed 2001 KX76, this object has an estimated diameter of 1,270 kilometers, making it the largest known member of the belt. Charon, in comparison, has a diameter of about 1,200 km, and Pluto is 3,300 km across.