Pluto, the small, frozen dwarf planet at the edge of the solar system, has been officially declared the largest known world in its neighborhood. The planet is just one of many icy bodies in the Kuiper Belt, a vast debris ring beyond the orbit of Neptune. There’s been some uncertainty over the last decade about whether Pluto is the biggest among those worlds, or if recently discovered dwarf planet Eris might take that title.

Today, we wonder no longer.

“Pluto is a little bit larger than we anticipated,” said New Horizons principal investigator Alan Stern at a press conference this morning. “That settles the debate about the largest object in the Kuiper Belt.”

Scientists on the New