On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

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 ...

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 ...

A fresh study of the Kuiper Belt’s structure has revived that far-out question, pointing to a possible Earth-sized ...

If the solar system does have a Planet Nine, it is a world that was bullied by its larger siblings, exiled to the far reaches of space and only rescued from oblivion thanks to the intervention of ...

LONDON — 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 ...

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 ...

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 ...

Carbon dioxide has been detected on a planet outside our solar system for the first time. The gas has been observed directly by the James Webb Space Telescope on four exoplanets, all belonging to the ...

Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar system. It’s an unprecedented ...

While its star projector leaves a lot to be desired, the Science Can Solar System Planetary Projector is a fantastic educational tool for kids, with its solar system model, complete with talking ...