Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

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. When ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...