How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

A dwarf planet is classified as a celestial body that orbits the sun that has enough mass and gravity to be mostly round, but unlike other planets, has not cleared its orbital path of asteroids ...

The planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. If you include the ...

A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system. The object—which orbits out beyond Neptune—has been named "2017 OF201" by the ...

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 ...

The solar wind pushes some of the gas and dust away from the comet, forming those beautiful tails we see. A comet actually ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

Computer simulations show that planets could be flung out of the inner solar system, supporting the possible existence of a ...