Researchers believe that 2017 OF201s highly eccentric orbit points to a chaotic origin, possibly caused by a gravitational ...

How long does it take Pluto to orbit the sun? Learn more about how this planet makes one lap around our Solar System.

Many people hold Pluto close in their hearts and refuse to abandon the assertion that it is a planet, although science ...

In 2006, the IAU determined Pluto did not meet the qualifications to be a planet because it doesn’t clear its orbital path like the other planets do. Mercury’s diameter is bigger than dwarf ...

OF201, the object belongs to the same all-star family as Pluto: dwarf planets. Its diameter, roughly 435 miles (700 km), is ...

When did Pluto stop being a planet, and why? Pluto was always in a tough spot when it came to being a planet. Just 1,477 miles across, it's only one-fifth the diameter of Earth.

Since Pluto is so far from Earth, little was known about the dwarf planet's size or surface conditions until 2015, when NASA's New Horizons space probe made a close flyby of Pluto.

Pluto hasn't been a planet for almost 20 years. In the early 2000s, scientists discovered several objects of a similar size to Pluto. So, during the summer of 2006, members of the International ...

Though Pluto has formally been considered a dwarf planet for almost two decades, it still has many lessons left for planetary scientists — including hints about how the solar system formed.

Pluto likely acquired large moon Charon in a “kiss and capture” collision billions of years ago. It may have created a subsurface ocean on the icy dwarf planet.