Editor's note: We've received thousands of thoughtful responses, both for and against Pluto's planethood. Here is a representative sampling:

From Prof. Paul Rybski, Chair, Physics, University of Wisconsin-Whitewater:

"I favor the original IAU two-part definition of planet: roundness and Sun-orbiting. Yes, it lets in Ceres and probably Pallas as well as Pluto and Xena -- and who knows what other planets there are to be discovered. But so what? This two-part definition at least eliminates most asteroids and all moons. It adds new worlds to explore to our solar system and could substantially inspire young people to study astronomy. Reducing the number of planets in the solar system would be substantially less inspiring."

from Shana M. Buck, home school teacher:

"Our family (two parents, 8 kids) vote for Pluto to keep its planet status -- for now! But here's a thought: Why did astronomers vote on this now, instead of after New Horizons reaches Pluto? Isn't it kind of -unscientific- to make bold declarations as to whether Pluto is or is not a planet, knowing that a plethora of new scientific data about Pluto and Charon will most likely be on the way back in just 8+ years? I'm glad to see that scientists are just as prone to dumb decision making as the average person."

from Dr. Alan Cayless, chairman of the Stirling Astronomical Society:

"I see no reason why we should not invoke the principle of Grandfather Rights. In effect, this says that when a rule is tightened or reviewed, that people (or in this case, planets) who qualified under the old system are allowed to retain their existing status, even if they would not qualify under the new rules. A good example is when planning regulations for buildings are changed: new buildings have to conform to the new, tighter, regulations - but older buildings constructed under previous rules are allowed to stand: they don't have to be demolished simply because they don't comply with the new rules. Grandfather Rights would allow Pluto to retain its 76-year-old status as a planet, whilst avoiding the problem of having to add others such as Sedna. There is plenty of precedent for this in science: electrons still have a negative charge, planetary nebulae are still called 'planetary' nebulae, even though they have nothing to do with planets. I hope the IAU will consider this seriously, as a practical and workable compromise."

from 5th grade teacher Pidge Wingert and her Gifted Students in Albequerque, New Mexico

"We think that the decision shouldn't be left to the public but decided by the scientists who have studied the planets for years. We, as a class, disagree amongst ourselves about Pluto being a planet; we are divided 50-50."

from Dr. Paul Richardson, a family doctor and amateur astronomer

"The arguments of the IAU are irrefutable. Pluto is a big member of a group of many objects, and should never have been classified as a planet - although the reasons it was are fully understandable within their time. If schoolkids want a planet to call their own, they should adopt Mercury--much more exciting than sluggish Pluto from which the sun looks like a bright star."

from John Chumack, astrophotographer

"Four percent of the astronomical community is not enough for a decision this big. It has many public, historical, and scientific ramifications. This should be decided by the people of the world as well, not just scientists."

from James N. Head, JPL Solar System Ambassador - Contra Costa County area

"Making Pluto a minor or dwarf planet enhances our understanding of our Solar System. So along with Ceres, and "Xena", and the asteroid belt, and the Kuiper belt, and the Ort cloud, the Solar System is seen as a more complex structure, more elegant, more sophisticated, and our experience is enriched. If, on the other hand, we make Pluto a planet, then dozens of other planets will be added. It will be a mess - what child is going to remember thirty planet names--or hundreds?"

from Leigh Palmer, Professor Emeritus, Department of Physics, Simon Fraser University

"Pluto is a planet in our (Euroamerican) culture. In the last cultural shift of this nature the Sun was promoted from planet to the center of the universe, the Moon lost its planetary status and Earth was demoted to planetary status. There were good scientific reasons for these changes. It would be an example of extreme conceit for the IAU to assert it is capable of effecting a cultural shift of comparable magnitude for a trivial nonscientific reason."

This page is under construction. Come back tomorrow for more responses. --Dr. Tony Phillips