Planets usually stay close to their host stars, tracing steady paths shaped by gravity. Yet some planets break free and drift ...

A rare alignment of two exoplanets with their star, marking one of the few known exosyzygies, an astronomical event involving ...

For the first time, astronomers have directly measured the mass of a rogue planet, a celestial body wandering through space ...

A lucky alignment of space- and ground-based telescopes has enabled researchers to nail down the mass of a rogue planet for the first time. Unlike worlds in our Solar System, rogue planets do not ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Somewhere between the stars, far from any sun, a planet is moving quietly through space. There is no orbit to trace and no ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

INDIANA, USA — Stargazers, mark your calendars! A rare seven-planet alignment will be visible in the early night sky in late February 2025. While we’ve enjoyed a six-planet alignment since mid-January ...

INDIANA, USA — As soon as the sun sets, step outside and look up to witness a rare celestial event: full planetary alignment. Between Feb. 23 and Feb. 28, 2025, all seven planets will align in the ...