Out in the dark abyss, past the large gaseous giants, tiny Pluto used to orbit the Sun as the ninth plant in our solar system. But no longer.

Thursday, the International Astronomical Union created a new definition of “planet,” stripping Pluto of its former title. The IAU now describes a planet as an object that has enough mass to form itself into a sphere, orbit a star and clear the area around it, according to Robert Egler, professor of physics and senior lecturer of astronomy.

The debate surrounding Pluto’s status began years ago with the discovery of multiple large objects in Pluto’s vicinity, Egler said. These objects became members of the Kuiper belt as minor planets, the formal name of asteroids.

“There are a lot of scientists that said they didn’t think [Pluto] was a planet,” Lisa Lowe, a graduate student in physics, said.

The controversy intensified when astronomers discovered an object larger than Pluto, nicknamed Xena, and identified it as a minor planet.

“If you discovered Pluto today there would be no debate that it was not a planet. It is only 75 percent of the moon; it is a tiny little object,” Egler explained. “It’s orbit is different from other planets, bringing it inside the orbit of Neptune. Pluto’s orbit is also at a 17 degree angle while all the planets orbit on a flat plane.”

Pluto’s composition is also mostly ice, making it more similar to a moon, and it has a satellite named Charon that is at least half of its size, according to Egler. All of these factors greatly distinguish Pluto from the eight major planets in the solar system, but still people cling to Pluto as a planet.

When discovered 75 years ago, Pluto’s size could not be calculated and it became the ninth planet. Historically, Egler said he sees Pluto as a planet regardless of the definition changes.

“In real life there is a continuum of objects,” Egler said. “And you have to come up with a line to draw for what is a planet and what is not. A planet was something orbiting a star with enough mass to be spherical, but now that has changed… If it was still the case there would be like 30 planets in the solar system.”

Lowe said she views the change as more of a technicality than anything else, since teachers always had to explain the differences between Pluto and the other planets — but that now the classifications will make more sense.

Egler joked that one of the biggest changes regarding Pluto’s new classification is he would no longer being able to use one of his favorite trick questions. “I used to ask what currently is the furthest planet from the Sun,” he said. “But now it will always be Neptune.”

Although Pluto’s demotion to a minor planet may not be life-altering, “It’s going to be weird,” Justin Nuzum, a freshman in business management, said.