It's been 20 years since Pluto was declassified as the ninth planet in our solar system, and many people wish it had never lost its status. A recent comment from NASA Administrator Jared Isaacman ...

Kaela Polkinghorn sat in the darkened dome theater of Tampa’s Museum of Science and Innovation and watched eight planets ...

Add Yahoo as a preferred source to see more of our stories on Google. A recent research paper suggests that a planet may exist far beyond Neptune — less than 20 years after the previous ninth planet, ...

On July 14, 2015, NASA's New Horizons spacecraft arrived at Pluto for the first time. The craft flew within 7,700 miles of the planet and is sending back reams of data and the highest resolution ...

A 10-year-old's earnest letter to NASA, politely requesting Pluto's planet status be reinstated, captured global attention.

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

"Orbiting at the edge of the outer Solar System, Pluto is an intriguing object in astronomy. Since the fascinating events surrounding its discovery, it has helped increase our understanding of the ...

A researcher has used advanced models that indicate that the formation of Pluto and Charon may parallel that of the Earth-Moon system. Both systems include a moon that is a large fraction of the size ...