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

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

“Meanwhile, its perihelion—the closest point on its orbit to the Sun—is 44.5 times that of the Earth’s orbit, similar to Pluto's orbit.” This extreme orbit, which takes the object ...

Pluto has become a beloved object in our solar system ever since the International Astronomical Union (IAU) reclassified it from a planet to a dwarf planet back in 2006 – a decision which has ...

At the very edge of our solar system, beyond the grasp of Neptune and even past the icy sprawl of Pluto’s domain, a new ...

An international team used 40 years' worth of data from two space probes to track down what they believe are signs of this ...

At the very edge of our solar system, beyond the grasp of Neptune and even past the icy sprawl of Pluto’s domain ... among a class of objects known as extreme trans-Neptunian objects (ETNOs).

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar system, announced the discovery on May 21. At roughly 435 miles wide, 2017 ...