According to Dr. Grundy, Pluto is a planet. "I use the word 'planet' to refer to it, and most of the planetary science ...

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

As the gatekeepers to the Kuiper Belt, Charon and Pluto are a unique double dwarf planet system. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it ...

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

Pluto is a dwarf planet; humans declared it to be one in 2006 since it is so small. It has little “ice mountains” on the surface. Scientists think the inside is actually water. Pluto’s ...

A blue atmosphere, smooth areas, and youthful mountain ranges - this dwarf planet is full of surprises. When NASA's New Horizons probe flew past Pluto in July 2015, the images it returned astonished ...

One idea is that Pluto got its moon system when a massive object smashed into the dwarf planet. The resulting debris then formed into the moons. This hypothesis was nicknamed the “Big Whack.” ...

For one reason or another, some people are still upset about Pluto's demotion from planet to dwarf planet. This demotion, by the way, occurred all the way back in 2006. So, what does famed ...

Named after the Goddess of strife and discord, Eris was estimated, at the time, to be larger than Pluto ... a new class of dwarf planets and made a lot of people angry. Still, kids in school ...

Planitia structure on its surface. Ever since NASA's New Horizons sent back the first-ever photos of Pluto in 2015, the dwarf planet's mysterious heart-shaped region has puzzled scientists.

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 ...

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.