Back in the 1980’s, a now-defunct magazine called Science Digest held a contest to name Planet X — the still-undiscovered world that astronomers believed might lie out beyond Pluto. One of the best ...

This composite image of Pluto, right, and Charon, its largest moon, showcases photos captured by NASA’s New Horizons spacecraft in July 2015. Unlike how scientists believe Earth's moon formed billions ...

The love story between Pluto and Charon may have started with a kiss. A new study suggests the dwarf planet and its scarcely smaller moon likely came together in a collision that saw them conjoined ...

Pluto landed its largest moon, Charon, with a 'kiss'—overturning decades of scientific assumptions about how planetary bodies form and evolve. This is the conclusion of a new study, conducted at the ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. For decades ...

The space probe began making discoveries even before today's flyby. — -- Three billion miles and nearly ten years of travel led up to the moment NASA's New Horizons probe zoomed past Pluto today, ...