The half-lit lunar disk will rise alongside the ringed giant Saturn and dimmer Neptune in the early morning hours of June 19, ...

In the remote outer reaches of planetary systems, far beyond the orbit of known planets, enormous and mysterious worlds silently loop around their stars. Some drift as far as 10,000 times the distance ...

Researchers now appreciate that gas planets are more complex than first thought. New findings have implications for our ...

Learn how a new discovery of a giant planet can help scientists refine their theories of how planets form.

Artist's impression of Planet Nine – a suspected “wide-orbit” planet – with the Sun in the distance; Neptune's orbit is shown ...