Mission scientists have found Pluto to be 1,473 miles (2,370 kilometers) in diameter, somewhat larger than many prior estimates. Images acquired with the Long Range Reconnaissance Imager (LORRI) were ...

Humankind got closer to Pluto than ever before on Tuesday morning, with NASA’s New Horizons probe flying just 6,000 miles from the former planet. The unprecedented proximity to Pluto has provided ...

NASA's New Horizons mission has answered one of the most basic questions about Pluto—how big is it? Mission scientists have found Pluto to be 1,473 miles in diameter, somewhat larger than many prior ...

The second part of this question is much easier to answer than the first. We will definitely get a different number for Eris’ size once a spacecraft visits it. Spacecraft measurements can be thousands ...

Pluto is a little larger than astronomers previously believed, the New Horizons spacecraft has revealed. This could reveal new information about the distant icy dwarf. New Horizons is the first ...

For the most part, our moon is nothing particularly special. It isn’t home to a series of active volcanoes, a thick atmosphere chalked full of nitrogen (with oceans of liquid hydrocarbons), or ...

The Hubble Space Telescope may be getting old, but it still has excellent spotting power — witness its discovery of a fourth moon of Pluto, which is between 8 miles and 21 miles in diameter. Says ...

In a universe full of planets, 2007 OR10 is something special. It’s big, just slightly smaller than the size of Pluto. And it’s close, within our very own solar system. So how did it still manage to ...

Astronomers looking for rings around Pluto have instead made an unexpected find: a fourth moon circling the dwarf planet. The object, temporarily designated P4, is probably the most dwarvish of ...