The ongoing debate as to what exactly constitutes a "planet" has aroused some ire among astronomers at the meeting of the International Astronomical Union in Prague. The planet definition committee offered three new definitions in an attempt to mollify the scientists that had rejected the first proposal. However, most of the scientists in attendance rejected these as well.

The latest proposal continues to define planets as round objects that orbit the Sun, but adds the following: "In our solar system, we distinguish between the eight 'classical' planets as the dominant objects in their local population zones, and 'dwarf' planets, which are not." This is an attempt to find common ground with the astronomers who had come up their own definition last week.

"They have presented practically the same resolution as before," says Julio Fernandez of the University of the Republic in Montevideo, Uruguay. Fernandez was one of the authors of last week's  proposal.  He added, "Most of the people here think it makes no sense."

It seems like hair-splitting. Everyone agrees that objects in Solar orbit fall into one of three categories: – the big planets from Mercury to Neptune; a number of "dwarf" planets (i.e. Pluto, Ceres, et.al.); and asteroids.  What subject of just what constitutes a "dwarf planet" seem to be the problem. Fernandez says they aren't planets at all, while the Committee says they are.  It's a small thing until you have to answer the question of exactly how many "official" planets actually orbit the Sun. 

A lunchtime meeting turned hostile when Fernandez tried to read his alternative definition.  He was cut off by Ron Ekers, the IAU president.  "I think it was disgraceful treatment," says Brian Marsden, formerly head of the Minor Planet Center in Cambridge, Massachusetts. As more questions were prevented, one astronomer cried out: "If there is democracy, listen to the questions. Let the people speak!" More of the scientists became angered when a  member of planet committee, MIT's Richard Binzel, said: "You can vote based on physics, or maybe you have some preconceived idea of what a planet should be."

Irish astronomer Mike Bailey said "With the present state of knowledge, it's impossible to draw the line between dwarf planets and asteroids." A final resolution declaring that a planetary companion can be a full-fledged planet  if its center of gravity of the system is out in space was rejected by most of those in attendance. That resolution would have made Charon a planet, leaving other planetary companions as moons.

Now there is an attempt to reconcile the warring parties' views in preparation of a vote on the subject coming up this Thursday.