Things have been a mess since Pluto's demotion. In 2006, the International Astronomical Union (IAU) voted on the definition of a planet. Famously, Pluto no longer met the criteria and was demoted ...

Nevertheless, because it orbited the Sun like a planet, it was classified as a planet and named Pluto, after the god of outer darkness in Roman mythology. So things stood for 65 years. Although ...

And if you are still a Pluto-is-a-planet holdout ... It sure would make it harder to build an orrery. His conclusion is simple and straightforward and has the ring of truth: the solar system ...

To underscore this point, a researcher at NASA created a simple new animation (below) that shows what light-speed travel looks like between from the sun to Pluto. James O'Donoghue, a planetary ...