If the task of naming planets were up to the public, there's good reason to believe Pluto would still be identified as a planet -- and not just one of the more popular characters in the Disney animated universe.

The topic of what exactly constitutes and planet and whether the designation should be given back to Pluto -- which lost its standing as the farthest-flung of the solar system's nine planets in 2006 and relegated to the status of plutoid, or dwarf planet -- was passionately considered in front of a live audience during a recent debate hosted by the Harvard-Smithsonian Center for Astrophysics, explained an organization news release.

The focus of the event was to revisit the age-old question: "what is a planet?"

To that end, the center invited "three leading experts in planetary science, each of whom presented their case as to what a planet is or isn't," the release said. "The goal: to find a definition that the eager public audience could agree on!"

As the scientific body that truly does hold the responsibility of dubbing celestial objects, the International Astronomical Union took up the planet definition at a meeting eight years ago.

While they mightily tried to settle on a definition on which everyone could agree, they couldn't, so Pluto's cosmic profile was determined by compromise, a definition the IAU accepted as a workable, but by no means perfect, option.

Hence, the current, official, disputed definition of a planet reads that it is a celestial body that:

  • ...is in orbit around the Sun;
  • ...is round or nearly round; and
  • ...has "cleared the neighborhood" around its orbit.

Yes, the definition has left people scratching their heads ever since, because, among other myriad reasons, it only applied to planets in our solar system -- begging a follow-up question: "What about all those exoplanets orbiting other stars?"

Nevertheless, Pluto was stripped of its planet title and send to the dwarf planet doghouse.

And, no, a dwarf planet apparently doesn't qualify as an actual planet, according to the IAU.

Warp forward in time to the Harvard-Smithsonian Center for Astrophysics debate Sept. 18, where science historian Dr. Owen Gingerich, who chaired the IAU planet definition committee, presented a historical viewpoint, while Dr. Gareth Williams, associate director of the Minor Planet Center, represented the IAU's stand and Dr. Dimitar Sasselov, director of the Harvard Origins of Life Initiative, presented the viewpoint of an exoplanet scientist.

Gingerich argued "a planet is a culturally defined word that changes over time," and that Pluto, therefore, is a planet.

Williams, the resident IAU definition defender, restated the official reasons why Pluto should not be considered a planet.

Sasselov defined a planet as "the smallest spherical lump of matter that formed around stars or stellar remnants," which means Pluto is a planet, along with a bunch of other objects orbiting the sun.

Finally came the gathering's piece de resistance, when the audience got to vote on the fate of Pluto and, by extension, the other potential planets, just waiting for their time, in the darkness of space.

Sasselov's definition won the overwhelming support of the gathering, which reaffirmed Pluto's status as a planet -- in their hearts and minds, but not yet anywhere else.

Headquartered in Cambridge, Massachusetts, the Harvard-Smithsonian Center for Astrophysics -- through which scientists, organized into research divisions, study the origin, evolution and ultimate fate of the universe -- is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory.