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Is Pluto Too Puny to Be a Planet?

It's the talk of the International Astronomical Union meeting, now underway in Prague. Astronomers are grappling over whether its small status should cause it to be declassifed as a planet.

Indeed, it's smaller than earth's moon and there are other objects past Neptune that are comparable in size to Pluto.

On the other hand, there are valid arguments to call Pluto a planet. It has an atmosphere, it goes through seasons, and it has three moons.

And what would happen to the mnemonic device for remembering planet names? You know: "My Very Educated Mother Just Served Us Nine Pizzas."

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As special correspondent and guest host of NPR's news programs, Melissa Block brings her signature combination of warmth and incisive reporting. Her work over the decades has earned her journalism's highest honors, and has made her one of NPR's most familiar and beloved voices.