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

At the center is the sun, a yellow dwarf star that contains 99.8% of the solar system's mass. Everything else — from the eight major planets to dwarf planets, comets, asteroids, and icy objects ...

For over a century, astronomers have wondered if there's an extra planet in our Solar System that we haven't been able to see ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

Astronomers may have found a candidate for Planet Nine. This planet is beyond Neptune. The finding could be the first ...

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

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

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, ...

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about ...

Jupiter is the largest planet in the solar system. It's about 11 times wider than Earth with an equatorial diameter of 88,846 ...

sitting in the Kuiper Belt - a region in our solar system beyond Neptune filled with icy objects, comets, and dwarf planets like Pluto. Since this hidden planet may be so far away, the new study ...

Pluto remains a fascinating and beloved part of our solar system with a slightly less glamorous title. At this moment, Pluto is still classified as a dwarf planet. Despite ongoing debate and ...