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

The giant-impact hypothesis posits that billions of years ago a Mars-sized body named Theia collided with the early Earth.

Saturn, Venus, Neptune, Uranus, Jupiter, Mars and Mercury will be visible in an uncommon planetary alignment this month.

For a brief moment at the end of February, every planet will appear in the night sky simultaneously in a rare celestial ...

The dwarf planet 1 Ceres is in conjunction with the Sun at 5 P.M. EST today. While this means we can't see Ceres for now, we ...