The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

New research shows that star activity can distort exoplanet measurements, affecting size, temperature, and atmosphere ...

"Temperamental" stars that brighten and dim over a matter of hours or days may be distorting our view of thousands of distant ...

Asteroids are rocky objects that orbit the Sun, just like planets do. There are millions of asteroids of very different shapes and sizes. Some are almost spheres, like planets, but most are ...

Temperamental' stars that brighten and dim over a matter of hours or days may be distorting our view of thousands of distant planets, suggests a new study.

Just six light-years from the solar system — in cosmic terms, our backyard — exists a world about half the size ... planets. In addition to discovering Barnard’s b — a completely different ...

"Pluto and Charon are different—they're ... complex bodies despite their small size and cold temperatures,” NASA said. Pluto may not be a full-fledged planet, but it continues to fuel ...