Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for ...

Every planet takes its turn going retrograde, and since Sunday, May 4, Pluto, the planet of transformation, has moved backward through the zodiac, presenting a chance to go inward and find new ways to ...

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 from a planet to a dwarf planet in 2006 by the International Astronomical Union. The main reason for Pluto's demotion is that it's not able to "clear its orbit of debris." Other ...

Pluto may have been demoted to non-planet status, but it still commands a court of five moons, as is fitting for the king of darkness; after all, Pluto is the Roman equivalent of the Greek God Hades.

In 2006, a vote by the International Astronomical Union determined that Pluto was no longer a planet. The decision sparked a heated public debate, and many planetary scientists disagreed with kicking ...

For no explainable practical reason, humans are enamored with – and even empathetic toward – specific inanimate objects. Our first car. A choice coffee mug. And for a particular subset of the ...