Reference Explore the eight (or nine) planets of the solar system in order from nearest to the sun and discover the many wonders of our solar system along the way. An object seen to have moved in the ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

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.

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

A giant object that has been lurking in the relative galactic vicinity of the Solar System this entire time has just been ...