The solar system lost its ninth planet back when Pluto was demoted to a dwarf planet, but research might indicate that there is a distant Planet Nine out there.

Pluto has long been one of the most debated celestial bodies in our solar system. Once classified as the ninth planet, it was redefined in 2006 as a dwarf planet, a decision that still sparks ...

NASA's New Horizons spacecraft captured this high-resolution enhanced color view of Pluto that is inserted beneath the Short Wave logo. The image combines blue, red and infrared images taken by the ...

Pluto's unusual eccentricity and tilt is likely due to its interactions with neighboring Neptune and other giant planets, ...

A recent research paper suggests that a planet may exist far beyond Neptune — less than 20 years after the previous ninth planet, Pluto, was demoted. That research paper, accepted last month for ...

In 2006, updated research led to Pluto being controversially demoted to dwarf planet status by the International Astronomical Union. The reasoning was that Pluto's location in the far-flung ...

The methane gas may constitute a rarefied atmosphere, or it may come from erupting plumes on Makemake’s surface.

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 ...

Though Pluto has formally been considered a dwarf planet for almost two decades, it still has many lessons left for planetary scientists —... Pluto isn’t a planet — but it gives us clues for how the ...