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 before shoving four of the solar system's planets onto a different course.

Scientists believe that two asteroids might be fragments of long-lost "planetary embryos" from the early solar system.

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

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

Though all the eight major planets of the Solar System revolve around the Sun in ... of it from human's point of view and this allows its size and orbit to be noticed with difficulty.

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien astronomers could also be scanning Earth.

The new exoplanet, Enaiposha, also known as GJ 1214 b has never been seen before and is now officially being called a "Super-Venus." ...