The New Horizons spacecraft passed Pluto on Tuesday, according to NASA, establishing that mankind — or at least one of its robot probes — has now visited the far reaches of our planetary system. “It’s ...

From the time of its discovery in 1930 until 1992, Pluto was a happy, full-fledged planet. A little odd maybe with its tipped, eccentric orbit and tiny size, but the ninth planet just the same. That ...

On Aug. 24, 2006, the International Astronomical Union voted to strictly define a planet, which ultimately downgraded Pluto from the ninth planet from the sun to a dwarf planet — causing controversy ...

A recent study introduces the idea of Planet Y, a theoretical world that could explain strange gravitational behavior beyond ...

NASA has released a new video showing what it might be like to land on Pluto with a brand-new view of the dwarf planet's surface. The space agency’s New Horizons spacecraft spent about six weeks in a ...

Perhaps the most significant astrological shift taking place this year is that Pluto, planet of death and rebirth, will be moving into revolutionary Aquarius for the first time in 225 years. Jeffrey ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...