Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Many Americans grew up with this as the definitive planetary lineup and created clever mnemonic devices to memorize them in ...

PRAGUE, Czech Republic ” For decades, it’s been confused with a cartoon dog and ridiculed as a puny poser. Now Pluto, the solar system’s consummate cling-on, has suffered its worst humiliation: It’s ...

It’s been 18 years since Pluto’s celestial status was called into question—yet the matter seems far from settled. We asked experts from both sides to make their case. This 2015 NASA image of Pluto ...

For such a small member of the solar system, about which relatively little is known, Pluto has an impressive following. When the news that the ninth planet had been stripped of its planethood got out, ...

The debate over Pluto’s planetary status has been ongoing since its reclassification as a “dwarf planet” in 2006 by the International Astronomical Union (IAU). Recent discussions and new scientific ...

Pluto was downgraded to dwarf planet over 10 years ago, but it's something that still seems so damn unfair. How do you take away its planet status after 76 years? On the other hand, science is ...