Which way is ‘down’ has a different answer depending on where you are on Earth, in the solar system, in our galaxy and beyond ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

Not much, unless we're talking about spacecraft. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. For the last month and change, you might've seen ...

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 ...

AMES, Iowa – Using data from NASA’s Kepler space telescope, an international team of astronomers has discovered a distant planetary system featuring multiple planets orbiting at a severe tilt to their ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...