The object’s aphelion the farthest point on the orbit from the Sun is more than 1,600 times that of the Earth’s orbit,” said ...

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 ...

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

A newly identified dwarf planet, named 2017 OF201, has been discovered in the distant outer reaches of the solar system.

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

There's no shortage of round celestial objects in our universe. Planets, moons and stars all exhibit lovely spherical shapes.

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

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

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

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

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