From Mercury to Neptune, observers in the United States will get to see this historic planet parade known as a large ...

The eighth and most distant planet from the sun, Neptune, reaches opposition with the sun on Sept.23, when it will be in its best position for viewing for the year. Neptune is too faint to see with ...

A team of astronomers has announced the discovery of some of the smallest planets yet detected beyond our solar system. The two newly discovered planets represent a new class of extrasolar planets, ...

It's not often that planets align in the night sky. Attention, stargazers: Another celestial phenomenon is set to appear in the night sky Friday evening. Seven planets -- Mars, Jupiter, Uranus, ...