When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Our solar system contains objects ranging in size from the sun, the largest item, to tiny grains ...

A planet's appearance is determined by its composition and atmospheric conditions. Inner planets are rocky due to the Sun's heat, while outer planets contain more gas. Atmospheric gases and surface ...

Arlington, Va.–A team of astronomers has announced the discovery of some of the smallest planets yet detected beyond our solar system: two worlds that represent a new category of extra-solar planets, ...

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home. The solar system is our cosmic neighborhood, made up of the ...

Thanks to NASA's Hubble telescope, planet HD 189733 b has become the first planet outside the Solar System to have its color directly measured -- and, like Earth, it's blue! Unlike our home planet, ...