Sedna is drifting into a part of its path where human technology can finally contemplate catching up, and that window will ...

A surprising chemical difference between Pluto and Sedna, another dwarf planet in the distant Kuiper Belt, is helping scientists nail down their respective masses, a new study reports. "Kuiper Belt ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. An illustration of confirmed dwarf planets and their moons. From left to right: Pluto (with ...