A group of German astronomers organized themselves into a Missing Planet ... Mars and Pluto), not even the meanest of teachers would require students to learn all their names.

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.

Everyone's favorite dwarf planet, Pluto, was discovered just 95 years ago. Here's the story of how the once-ninth planet was ...

When New Horizons reaches Pluto, it won’t stop ... Of the 30 most Earth-like planets, seven share his name. As we enter the next stage of planetary science, he’s going to become a retroactive ...

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 ...

Venetia’s grandfather was reading the account of the new planet aloud from the paper and the young girl straightaway ...

Should Pluto be demoted? And what exactly is a planet, anyway ... pending a formal name, it remains 2003 UB313.) This file image provided by NASA's Hubble Space Telescope team on April 11 is ...

And if you are still a Pluto-is-a-planet holdout, like we were ... into simple classification schemas. What’s in a name, anyway?

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

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