Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's ...

On the 95th anniversary of its discovery, Pluto remains one of the most beloved and enigmatic worlds in our solar system, ...

Pluto will mark a birthday of sorts on March 23, 2178. No one is likely to be there to celebrate it, of course. Even if ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Pluto failed to meet that third criterion, so it was reclassified as a “dwarf planet” on Aug. 24, 2007. Critics point out that by that criterion, the Earth is also not a planet: We constantly ...

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

However, in 2006, the International Astronomical Union (IAU) redefined what constitutes a planet, leading to Pluto’s reclassification as a dwarf planet. This decision sparked widespread debate ...

Explore Ceres, the largest asteroid in our solar system, and discover its remarkable ancient ocean and ice-rich crust.

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...

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 ...

Pluto, our planet of profound change and ultimate reckoning, has set up shop in Aquarius, and the energy of the dwarf daddy of death’s transit will have a weighty effect on all of us.