With sapphire waterfalls, lava rain and orbits around dead stars, these distant worlds push the limits of what’s possible.

For centuries our solar system was the only planetary system known to humans. We had no proof other worlds existed beyond those in our own cosmic backyard, and we imagined that if other planetary ...

NASA has taken a bold step in the search for alien life beyond Earth. The space agency announced the selection of seven ...

Across the Milky Way and beyond, planetary systems appear to fall into a few recurring blueprints, and recent exoplanet ...

Short-lived radioisotopes such as aluminum-26 influenced early solar system heat, water retention and the formation of Earth-like rocky planets, according to meteorite analyses and models.

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 ...

From Viking to Perseverance, scientists have spent decades chasing chemical hints that could point to life beyond Earth.

When two giant planets collide, an even bigger world may be born. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Based on new simulations, ...

Most planets are part of a star system of their own – but some go their own way, and they have remained largely mysterious ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of ...