A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

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

Earth has a new neighbor that lives far, far away. Scientists from the Institute for Advanced Study's School of Natural ...

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural ...

WASHINGTON >> Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

Astronomers have announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond ...

Learn about the recently discovered trans-Neptunian object that may eventually join Pluto as a dwarf planet, found at the ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System — a ...