Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

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 ...

Before Pluto was discovered, it was predicted. Astronomers had observed that massive objects can affect the orbits of their neighbors and, after seeing deviations in the orbits of Uranus and Neptune, ...

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all the ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague? If ...

Pluto, once considered the ninth planet, was reclassified as a dwarf planet in 2006 because it shares its orbital path with ...

Our solar system is much like a trail of microcosmic breadcrumbs: Follow the molecular bits as far back as they go, and you'll learn a thing or two about where many of our planets and other celestial ...

Lowell Observatory's sixth annual "I Heart Pluto Festival" will honor the remote icy world that was reclassified as a dwarf planet in 2006 When you purchase through links on our site, we may earn an ...