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 ...

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today." When you purchase through links on our site, we may earn an affiliate ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

“The object’s aphelion—the farthest point on the orbit from the sun—is more than 1,600 times that of Earth’s orbit,” Institute for Advanced Study’s Sihao Cheng mentioned in a recent press release. As ...