Pluto relegated to the underworld

[mcgillianaire]

The International Astronomical Union has redefined our solar system by declaring Pluto to be a dwarf planet. As a result, there are now only 8 true planets & 3 newly-created dwarf planets.

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Comments

[pappubahry.livejournal.com]

About time.

Though one of the astro PhD students thinks that Pluto should have stayed a planet, since you need it to explain perturbations in Neptune's orbit.

[mcgillianaire.livejournal.com]

Perturbations?

[pappubahry.livejournal.com]

Imagine the universe is just the sun and Neptune. Essentially, Neptune orbits the sun in a slightly elliptical orbit. Now put the other planets in there. The gravity of the other planets perturb Neptune's orbit.

[gpaciga.livejournal.com]

The fact that something perturb's a planet's orbit does not mean that that something should also be a planet. Everything in space perturbs everything else.

[pappubahry.livejournal.com]

I agree that Pluto shouldn't be a planet, but I'll trust my astro friend when he says how influential various objects are in planetary orbits.

[gpaciga.livejournal.com]

I'm not saying it's not influential, I'm just saying that that's not good criteria for being a planet. I'm in physics as well, by the way.