Trans-Neptunian objects (TNO) are some of our solar system's lesser-known objects. They number in the thousands, and they get their name from their orbits. These dwarf planets orbit the sun at a greater average distance than Neptune does.

How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between five and 18, plus hundreds of potentially undiscovered ones, depending on whom you ask.

A whole universe of hidden galaxies lies just beyond what the eye can see. Thanks to a new generation of space telescopes, astronomers are now revealing these distant, dim worlds—some no bigger than a fraction of the Milky Way but holding clues to how the universe took shape.

But Pluto turned out to be too tiny — it is smaller than the moon — and was demoted to dwarf planet status in 2006. There are now four other officially recognized dwarf planets, and Cheng ...

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 ...

Astronomers have discovered a freezing-cold world orbiting within the so-called "forbidden zone" around a dying star in which planets are normally destroyed.. The 5.8-billion-year-old white dwarf ...