All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

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

Our Solar System is a carefully balanced celestial dance held together by a virtually perfect balance of gravity and inertia.

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...

The Sun is the largest object in the Solar System. The Sun’s huge gravitational field keeps many other objects – planets, dwarf planets, asteroids and comets – in orbit around it.

Kuiper Belt, well past the orbit of Neptune (artistic illustration). There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond ...