Redefining Planets

I have been hearing about this redefinition process going on with the IAU and the basic definition of planet sounds good to me.

“A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet.”

Not that I get a vote on it. But, I would suggest one additional qualification. That the celestial body have a mean radius greater than 2000 km. Eventually, gravity will let all aggregates form into spherical shapes. For a planet, size matters as well.

For those bodies that have a mean radius of 500-2000 km, let them be called plutons, or minor planets, or something similar.

Let bodies with a mean radius of less than 500 km be asteroids or space junk or dark matter. Things to blow up as you are escaping the Empire’s Star Cruisers.

The Thoughts and Luminations of Jack Heneghan