If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

Vesta, thought to be the second-largest asteroid in the solar system, could be a piece of an ancient, unknown planet, a new study hints.

Astronomers have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.

Using two infrared space telescopes and a 23-year gap, scientists may have spotted a mysterious, slow-moving object beyond ...

Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why ...

Vesta might be a shattered remnant of an early planet, not a failed one—forcing scientists to rethink how worlds begin.

"This measurement of the planet population from planets somewhat larger than Earth all the way to the size of Jupiter and ...

A giant object that has been lurking in the relative galactic vicinity of the Solar System this entire time has just been unmasked in all its enormous, invisible glory.

New data from the James Webb Space Telescope suggests a planet in a faraway solar system was consumed by a star by hurling ...

As the second-largest object in the main asteroid belt, Vesta attracts a healthy amount of scientific interest.