Scientists who support Pluto’s status as a planet are not going down without a fight. More than 300 planetary scientists and astronomers have signed a petition attacking the decision last week by the International Astronomical Union to demote Pluto and relabel it as a “dwarf planet” (The Chronicle, August 25). The rebellious scientists state: “We, as planetary scientists and astronomers, do not agree with the IAU’s definition of a planet, nor will we use it. A better definition is needed.”

The generals leading the charge in the fight are Mark Sykes, director of the Planetary Science Institute, in Tuscon, and S. Alan Stern, a planetary scientist at the Southwest Research Institute and the leader of NASA’s New Horizons mission, which is currently speeding toward Pluto. The two researchers said in a news release on Thursday that it would have been better for the union to have included more of its members in the decision. Fewer than 500 of the union’s nearly 10,000 members took part in the recent vote, they said.

In a separate statement on the petition’s Web site, they wrote: “The IAU is incapable of correcting this action until its next General Assembly, in 2009. In the meantime, the IAU definition will stand as a source of confusion and incongruity to educators and the public. An alternative is needed.

“Planning is under way to establish an open and inclusive grassroots process by which planetary scientists and astronomers from around the world can approach a better resolution to the issue of planets in our own solar system and elsewhere, with every step and discussion in public view. This process should culminate in a conference, not to determine a winner, but to acknowledge a consensus.”

Stay tuned for more news from the protesters this month. Maybe by 2015, when the New Horizons spacecraft speeds by Pluto, we’ll know what to call it.

For background on the controversy, see Chronicle articles from 2005, 2001, and 1999.