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

Trans-Neptunian objects (TNOs) are icy bodies that vary widely in size, from large dwarf planets like Pluto and Eris—each ...

Astrophysicists have been grappling with the question of how water arrived on our young planet for decades. One of the ...

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

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

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.

In 2006, the International Astronomical Union (IAS) reclassified Pluto as a dwarf planet. That decision came several years after discovering the Kuiper Belt, a ring of icy and rocky objects 2.8 ...

Pluto shares its orbit with many other objects in the Kuiper Belt, according to International Astronomical Union. "A dwarf planet is an object in orbit around the Sun that is large enough to ...

And then, you have this third zone of icy dwarf planets, icy small bodies in the Kuiper Belt — and Pluto's the big one, the king of those. — 'What exactly is a planet?' Astronomers want to ...