Pluto is not a planet.

[bjarvis]

There, I've said it. I'm still dealing with the emotional aftermath of a solar system with only 8 planets, but I can now say it in public.

At best, it's a sizable Kuiper belt object, and an interesting one at that, but Pluto is not a planet.

Comments

[westwind-mv.livejournal.com]

Hey, if it can perturb Neptune's orbit then it qualifies to be a planet. Wasn't the reason Clyde Tombaugh was looking around Delta Geminorum in the first place because of calculations based on that perturbation?

Besides, the more the merrier! We just need a better name for the new planet ("2003 UB 313" just doesn't roll off the tongue).

[bjarvis.livejournal.com]

It was looking for something that perturbed Neptune but later calculations found that Pluto wasn't big enough to fit the bill; it just happened to be in the general area when Clyde was searching.

While I'm not absolutely sure, I believe the perturbations in Neptune's orbit were later found to be an error.