Pluto: Is It a Planet? Scientist States that Planet-Declaring is Arbitrary in Nature

First Posted: Jul 17, 2015 07:44 AM EDT

Is Pluto a planet or not? That's the debate that has raged for years. With New Horizons' flyby, though, researchers are gaining more information about the world and have finally come to a conclusion.

Back in 1930, Pluto was a planet because we couldn't see anything else brighter at a similar distance away from us. Then, in the 1990s, astronomers began detecting more planet-like objects around Pluto. This raised the question of whether or not the icy world was, indeed a planet. The only reason that Pluto was brighter was because it was icier and thus reflected more light.

"When it comes to Pluto, New Horizons' mission has taught us that it's bigger than we thought and its size was one of the reasons it was demoted," said Dejan Stojkovic, one of the researchers, in a news release. "We can label things what we want, but it's irrelevant because nature uses its own logic and as you can see, most of the time the two don't match up."

Two states, Illinois and New Mexico, actually passed laws declaring that Pluto would always be considered a planet. This shows the arbitrary nature of planet-declaring. Yet because Pluto has already been demoted to a dwarf planet, Stojkovic thinks it will remain that way.

"They won't sound serious if they keep going back and forth," said Stojkovic. "If they made Pluto a planet again, they would have to re-evaluate the definition of a planet and that would then put our moon in the planet conversation. I don't see that happening."

It seems that, for now, Pluto will remain a dwarf planet rather than becoming a planet.