Mood:

Every so often I will write an article about what's On My Mind (OMM). Today I will write about the Solar System and the reclassification on Pluto. In case you didn't know, Pluto is no longer considered a planet. The International Astronomical Union (IAU) has redefined the term planet. My opinion: finally, it took them long enough, and I don't understand the controversy.

Most people are more concerned with there no longer being nine planets than with the fact that Pluto is no longer a planet. The only problem with that is there wasn't going to be nine planets regardless! As scientists learn more, they must redefine things that were never true to begin with. The IAU had two definitions to choose from: one gave us 13 planets, and one gave us 8 planets. Either way, the 9 planet system we grew up with is gone.

Let's compare Pluto with other objects using Wikipedia as a source:

Firstly, the orbit. "Pluto's orbit is very unusual in comparison to the planets of the solar system. The planets orbit the Sun close to an imaginary flat plane called the plane of the ecliptic, and have nearly circular orbits. In contrast, Pluto's orbit is highly inclined above the ecliptic (up to 17° above it) and very eccentric (non-circular). Owing to the orbit's inclination, Pluto's perihelion is well above (~8.0 AU) the ecliptic. The high eccentricity means that part of Pluto's orbit is closer to the Sun than Neptune's."

Secondly, with comets. The Kuiper belt is believed to be the source for all short-period comets, and Pluto, like other Kuiper Belt objects, shares features in common with comets. The solar wind is gradually blowing Pluto's surface into space, in the manner of a comet. If Pluto were placed near the Sun, it would develop a tail, like comets do.

Finally, with Charon, Pluto's satellite. Pluto and its largest satellite, Charon, have often been considered a binary system because they are more nearly equal in size than any of the planetoid/moon combinations in the solar system, and because the barycentre of their orbits does not lie within either body.

In case you didn't get that, Pluto is just weird compared to the other planets. Also, I don't quite understand why so many people care so much about it. Sure, astronomers might care, but most people just need to have more important things to care about. Oh well.


-Paul Spangler

Sources for this entry:
http://en.wikipedia.org/wiki/Pluto

By Caroline
Mood:

That is very interesting. I missed that controversy. But you know people always have to make a mountain out of a mole hill. I'm most upset about not being able to use the nomogram "my very important mother just served us nine pizzas". Now its nine nothings. Just leaving us hanging.