Meet Tylos: a gas giant 900 light years away and with a climate never seen before on any planet known to scientists.

With each mass, she modeled 2 million years of orbit to find what kind of architectural impact each mass would have on our solar system. Specifically, she tracked changes to the other planets ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course.

The solar system is made up of the Sun (our nearest star) and the objects that orbit around it, including planets, asteroids and comets. Planets orbit the Sun in roughly circular paths ...

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.

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.