Pluto Is A Planet Argues New Research - And It Always Was

The debate over whether Pluto is a planet has been ongoing for years and there's no signs of that ending. New research out of the University of Central Florida argues against the 2006 definition that stripped Pluto of its status, citing research into 200 years of scientific literature on the requirements for classifying a planet.

The study follows a decision made in 2006 by the International Astronomical Union, a collective of experts in astronomy, who determined that a celestial body is required to clear its orbit to be classified as a planet. This was a problem for Pluto, which is influenced by Neptune's gravity, among other things.

With that definition, Pluto lost its planet status. The new research out of the University of Central Florida, however, argues against the definition of planet that requires the body to clear its orbit. According to researchers, 200 years of scientific literature didn't hold up the clearing-orbit requirement, only one publication from 1802 being the exception.

Talking about the work is planetary scientist Philip Metzger, who said:

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. And it would leave out the second-most complex, interesting planet in our solar system ... It's a sloppy definition. They didn't say what they meant by clearing their orbit. If you take that literally, then there are no planets, because no planet clears its orbit.

So what makes something a planet versus, for example, an asteroid? The researchers argue that intrinsic properties should be used to make the distinction, not things like orbit, which can change. Something like substantial enough gravity to form a spherical shape could be the defining factor, for example.

SOURCE: University of Central Florida