[djbebs]

Pluto is an order of magnitude larger than Ceres, so its perfectly possible to define planet in such a way that pluto is a planet and ceres is not.

[axaxs]

This is what I was thinking. Setting the minimum size to 2000Km diameter, and excluding satellites/mooons, we'd just have had to add one planet, if my reading is correct.

[chriswarbo]

It's hard to justify counting Pluto without counting Eris:

- Eris is more massive than Pluto (1.6e22kg versus Pluto's 1.3e22kg)

- Eris is only slightly smaller than Pluto, at 2326km diameter (more than your arbitrary 2000km cutoff)

- The orbit of Eris crosses Pluto's, so it may be closer to the Sun part of the time https://solarstory.net/img/articles/big/orbit-of-eris.jpg

[axaxs]

Agreed. Eris is the one I was referring to in my comment. Instead of removing Pluto, just add one planet(Eris).

On reread that probably wasn't clear, since I still think of Pluto as a planet.