In the original press release, Carl Pilcher, science director for solar system exploration in NASA's Office of Space Science, called the scale "a major advance in our ability to explain the hazard proposed by a particular NEO."

Binzel agrees that the process of approval did not strictly follow IAU guidelines, and that "where it is within the IAU is a fuzzy thing." But he points out that every effort was made to get the wording correct, and the IAU General Secretary approved the press releases.

Among researchers, these processes have not helped to buoy support for the Torino Scale as much as a more formal approach might have.

At Liverpool John Moores University, Dr. Benny Peiser moderates an often controversial but widely read scholarly electronic newsletter. Peiser's CCNet covers all aspects of what the professor calls neocatastrophism. Daily, asteroids and the threat of impact dominate the articles, news items, open thoughts and sometimes-biting criticisms.

Peiser, who supports the Torino Scale but expects it will need to evolve, says the controversy stems in part from the fact that it did not go through a proper review process. He says the details for refining the scale were entrusted to the IAU and the scientific committee at a June IMPACT meeting in Torino, Italy, where the scale was presented and approved (in principle, he notes).

"Given that significant objections in addition to relevant suggestions for improvement were made public at the IMPACT meeting, the failure to submit the Torino Scale for scientific review appears to have had a detrimental effect," Peiser told space.com.