Scientists hunting for the hypothetical Planet Nine have discovered a potential new dwarf planet, 2017 OF201, in the outer ...

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

Spotted beyond Neptune, the newly identified object follows an odd path through space, one that complicates a decades-old ...

It is an evocative idea: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all ...

It's an evocative idea that has long bedevilled scientists: a huge and mysterious planet is lurking in the darkness at the ...

Simulations show that the stars’ tug could send Mercury, Venus or Mars crashing into Earth — or let Jupiter eject our world from the solar system.

If humans ever decide to visit Uranus, they would die within five seconds. It would be quite a catastrophic journey before ...

A new study suggests the planet’s iconic domes owe their strange shape to both thick lava and a flexible surface.

Earth’s sister planet reaches greatest western elongation and dichotomy as the waxing Moon slides along the ecliptic in the ...