Two planets stand side by side as the evening twilight continues to delight and colorful stars shine in the sky this week.

NASA's New Horizons Pluto probe is gearing up to cross the "termination shock," an exotic boundary in the outer solar system, ...

The controversy endures over Pluto's true status, but the solar system underdog continues to capture hearts across the globe.

A bill from freshman Tucson lawmaker Kevin Volk would add 'howdy' to the extensive list of items mentioned in state statute ...

Explore Ceres, the largest asteroid in our solar system, and discover its remarkable ancient ocean and ice-rich crust.

Featuring a discussion on scientific exploration and how it inspires humanity, the keynote event for the sixth annual I Heart ...

What is happening in Earth's inner core? Discover the implications of its deformation for seismic activity and navigation.

Take advantage of a special 6-7 planet alignment from Earth's perspective. Planets 'line up' in the skies over California in February.

The "Star Trek" legend's only son will discuss his memoir at the annual space-themed event.

Binoculars will help. Astronomers at Caltech have just reported evidence for a giant planet far beyond Neptune and Pluto. Nicknamed Planet Nine, it has never been seen; instead, its presence was ...

Mercury tweets at breakneck speed, Venus flaunts on Instagram, Earth overshares on Facebook, and Pluto campaigns for planetary status on Change.org. Each planet portrays its identity vividly ...

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to ...