For the better part of a century, we believed there were nine planets in our solar system, with Pluto being the farthest from the sun. Since the discovery of more Pluto-sized dwarf planets, that ...

Apart from Pluto, which was demoted from a planet to ... an orbit similar to Sedna and more have been found since. The Planet Nine hypothesis was published by Brown and Konstantin Batygin in ...

Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...

Although Seeing in the Dark doesn't directly discuss Pluto, it does celebrate the joy of observing planets. Viewers who watch the show may wonder what happened to Pluto in 2006 and whether any of ...

Known as Planet Nine or Planet X, it is a hypothetical planet ... For more than 70 years, Pluto was classed as the ninth planet but that changed in 2006, when the International Astronomical ...

An curved arrow pointing right. NASA's New Horizons spacecraft took us to Pluto for the first time in July 2015. Scientists are astonished by the incredible features they've observed on the dwarf ...

The relative quantities of volatile gases like methane and ethane can reveal key details about distant Kuiper Belt objects.

Thomas says this goes for all outer planets: Jupiter, Uranus, Neptune and Pluto. “Jupiter and Saturn are the only outer planets that the ancients were aware of in previous times,” explains Thomas.

Forbes contributors publish independent expert analyses and insights. Jamie Carter is an award-winning reporter who covers the night sky.

A New Horizons image of Pluto and its moon Charon revealed more surprises about the dwarf planet and its orbiting moon. Click on the hand to see why Pluto and its moon have shaken things up.

Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...