The definition which demoted Pluto is “sloppy” according to University of Central Florida planetary scientist Philip Metzger.
• Has cleared debris from the area around its orbit (i.e. is the largest gravitational field in its orbit)
This last criteria saw Pluto be reclassified to a dwarf planet because it is circled by objects which together have a greater mass.
But pro-Pluto expert Metzger discovered that scientists studying our solar system over the past 200 years haven’t used clearing as a definition — because it’s useless.
"The IAU definition would say that the fundamental object of planetary science, the planet, is supposed to be a defined on the basis of a concept that nobody uses in their research," Metzger said.
"And it would leave out the second-most complex, interesting planet in our solar system."