Monday, July 21, 2008

How Many Planets? Part V

The answer is still eight major planets, but now there is a fourth dwarf planet. This is another plutoid, out beyond Neptune and was named Makemake by the International Astronomical Union a few days ago.

As mentioned last time we talked about this, there were two that were about to be named, officially, Easterbunny, aka 2005 FY9 and Santa. Makemake is the one formally known as Easterbunny.

Remember, Ceres, which originally classified as a planet, lost its status as more asteroids were discovered. Pluto lost its status as other objects, some larger than Pluto were discovered out in the area known as the Kuiper Belt. Ceres was elevated to dwarf planet and is still the only one not also classified as a Plutoid.

Makemake is about two thirds the size of Pluto and is a red methane-covered dwarf. It is thought to be slightly smaller than Pluto and isn’t quite as bright.

In case you think they deviated from the tradition of naming these objects after mythological gods, Makemake is the chief god among the people of Easter Island, which Mike Brown, who discovered the dwarf planet thought appropriate.

For those keeping score at home, we have eight planets, one dwarf planet orbiting between Mars and Jupiter, and three dwarf planets that are also Plutoids orbiting beyond Neptune. There will be more to follow


cda said...

It looks like Mike Brown & Chad Trujillo are making the traditional astronomy books semi-obsolete a bit too quickly. Even the new books can't keep up!

Cullan Hudson said...

Yes, I agree. There was a time when scientists sat on findings for a while to make sure they were correct in their theories before publishing. Now, it seems every new thing they spot is called a planet, then retracted, before another crops up only to be dubbed Snickerdoodle or Casper. The biggest crime? Those names!