Think you know your way around the solar system? From the scorching surface of Mercury to the icy edges of Neptune, our planetary neighborhood is full of wonders. The order of the planets isn’t just ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

If you're an early riser, you're in for a treat. On Sunday, Aug. 10, six planets — Mercury, Venus, Jupiter, Saturn, Uranus and Neptune — will line up in what is called a "planetary alignment." This ...

Lucas Brefka receives funding from a NASA Exoplanet Research Program grant. Christopher Palma does not work for, consult, own shares in or receive funding from any company or organization that would ...