Could the Planetary Status of Pluto Be Reinstated?

A long debated topic, the planetary status of Pluto may change once again.

A group of NASA scientists have proposed a new definition to the word “planet” that would allow Pluto’s status to be reinstated. It would also add tens of other bodies like Earth’s moon and moons like Titan.

The proposal by principal investigator of the New Horizons mission to Pluto, Alan Stern, claims that the current definition accepted by the International Astronomical Union (IAU) is too narrow and doesn’t follow what many people believe planets to be.

Stern has previously spoken out against Pluto’s demotion to dwarf planet.

“Why would you listen to an astronomer about a planet?” Stern said, according to, on the subject of the new definition of planet that came from CalTech astronomer Mike Brown instead of any planetary scientist. “You really should listen to planetary scientists that know something about this subject. When we look at an object like Pluto, we don’t know what else to call it.”

Stern and his group have proposed the following new definition:

“A planet is a sub-stellar mass body that has never undergone nuclear fusion and that has sufficient self-gravitation to assume a spheroidal shape adequately described by a triaxial ellipsoid regardless of its orbital parameter.”

The scientist claims that the new definition fits with the current commonly accepted definition of ”planet” even in some peer-reviewed planetary science publications.

One of the fundamentals of the proposal states that the IAU definition of a “planet” is “technically flawed.”

This new definition has historical precedence, sound scientific classification, and matches up with people’s intuition of “planet,” the proposal states.

However, even if the IAU accepts the new definition, it’s will take a significant amount of time to become official; so for now, Pluto will remain the source of outage on behalf of dwarf-planets everywhere.