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

Watch this video to find out more about the Earth, planets in our Solar System and other planets far ... of asteroids of very different shapes and sizes. Some are almost spheres, like planets ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

Speculation swirls as scientists debate if Planet Nine is a celestial body or something darker. Clues emerge from unexplained gravitational anomalies far beyond Neptune. A radical hypothesis ...

Your chart is ruled by Mercury, the fastest-moving planet in the solar system. Meaning, you tend to have trouble staying in ...

Astronomers believe that our solar ... system’s formation, extends far beyond Neptune and is home to Pluto and other dwarf planets. Astronomers believe that Planet Nine could be 5-7 times the ...

They developed a 3D model that simulates how the solar system's orbital architecture may have evolved differently with the formation of a planet that is at least twice the size of Earth's mass—a ...

The solar system may hold a hidden ... Neptune and includes Pluto and dwarf planets. Astronomers believe Planet Nine might be 5-7 times Earth’s size. It could orbit the sun 200 times farther ...