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

If everything in our solar system formed from the same solar nebula, why do the planets have different compositions ... But once the star ignites, the inner layers of dust heat up dramatically. As our ...

and these materials combined together to form the inner planets. The outer four planets (Jupiter, Saturn, Uranus, and Neptune) are called gas giants. When the solar system formed, gaseous ...