Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars. When you purchase through links on our site, we may earn an affiliate commission.

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...

WASHINGTON (Reuters) - Astronomers have identified a quartet of small rocky planets orbiting Barnard's star - one of our closest stellar neighbors - though they concluded that all of them are too hot ...

AMES, Iowa – An international team of astronomers has used nearly three years of high precision data from NASA’s Kepler spacecraft to make the first observations of a planet outside our solar system ...