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

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago. The find, announced ...

Scientists are tracking a large gas planet experiencing quite a quandary as it orbits extremely close to a young star—a predicament never previously observed. This exoplanet, as planets beyond our ...

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 ...

Mark Sykes says that if a non-stellar object is massive enough to be round and orbits a star, it ought to be a planet. The key here is that once an object gets that big, important geophysical ...

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 ...