Alan Stern, who is the principal investigator of NASA’s New Horizons mission to Pluto, was livid when Pluto was demoted from the official planet status. His interview back then had a certain,”I’ll be back to avenge” ring to it, and he is back with his latest proposal with a new definition of planets that would reinstate the icy dwarf rock back to its former glory.
The proposal has been submitted by Stern’s team to the IAU for approval, which asks for the redefinition of a planet as “round objects in space that are smaller than stars.” If this definition is approved, many other celestial objects like Earth’s Moon would be classified as a planet too.
Below is a more detailed description of the proposal for planetary classification;
“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 parameters.”
Stern’s bias towards making Pluto a planet can be understood from him being a part of the New Horizons mission. The mission had beamed back jaw-dropping pictures and information about Pluto, which was considered as a dwarf planet back then.
“You really should listen to planetary scientists that know something about this subject,” he said. “When we look at an object like Pluto, we don’t know what else to call it.”
Science Alert cites the proposal’s criticisms of the current planetary classification system:
- “First, it recognises as planets only those objects orbiting our Sun, not those orbiting other stars or orbiting freely in the galaxy as ‘rogue planets’,” they explain.
- Second, the fact that it requires zone-clearing means “no planet in our Solar System” can satisfy the criteria, since a number of small cosmic bodies are constantly flying through planetary orbits – including Earth’s.
- Finally, and “most severely”, they say, this zone-clearing stipulation means the mathematics used to confirm if a cosmic body is actually a planet must be distance-dependent, because a “zone” must be clarified. This would require progressively larger objects in each successive zone, and “even an Earth-sized object in the Kuiper Belt would not clear its zone”
Now the ball is in the court of International Astronomical Union. They have to pass the final verdict on whether or not to adopt this new definition.
Do you think Pluto should be given the status of a planet? Or would you prefer to have only eight planets in the Solar system? Comment below!