The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

NASA’s Voyager mission completed humankind’s first close-up exploration of the four giant outer planets of our solar system.

However, this year a powerful new telescope is coming online that could prove once and for all that there really is a ninth planet in our Solar System. The same year that Pluto was ignominiously ...

Despite common assumptions, the disk of our Solar System is warped, and the planets travel around the Sun in slightly eccentric (or oblong) orbits. Scientists now think that a mysterious object ...

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.

The James Webb Space Telescope has given astronomers groundbreaking insight into a new type of planet described as unlike anything in our solar system. The discovery of the exoplanet, which orbits ...

She mapped our solar system's "alternate fate" had it housed an extra planet between Mars and Jupiter instead of the existing asteroid belt. They developed a 3D model that simulates how the solar ...