The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact ...

Seven planets are aligning in the night sky this week, creating a brief chance to see a "planetary parade." Worldwide, the best day to see the alignment is today, Feb. 28. Mercury, Venus, Mars, ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

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 ...

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 ...

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 ...

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 ...

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 ...