One Astronomer's Impassioned Quest to Reinstate Pluto as a Planet

sarahnaomi writes: Most of us grew up believing that tiny, distant Pluto was the outermost planet in our solar system. Then, one day, the scientific powers that be decreed that it wasn’t. But it seems the matter is far from settled.

“The International Astronomical Union of wants to hide from the issue,” David Weintraub of Vanderbilt University told me in an email. “They have refused to allow the issue to appear on the agenda at the 2009 or 2012 or 2015 meetings. They hope it will go away.”

Weintraub—who describes Pluto’s exile as a stunt organized by a “very small clique of Pluto-haters”—would have the dwarf world rejoin the ranks of our Solar System’s fully-fledged planets today. But solid evidence that Pluto deserves the title may come in July, when NASA’s New Horizons spacecraft slingshots around the icy rock and sends us back a detailed picture of its composition.

Pluto’s planethood was revoked by majority vote on the final day of the 2006 IAU conference. Over 2,500 astronomers attended the meeting throughout the week, but only 394 votes ultimately decided Pluto’s fate: 237 in favor of demoting the planet and 157 against.