Tuesday, July 15, 2008

Say hello to planet Makemake

The International Astronomical Union has recognized a plutoid, or new dwarf planet, in our system with the name Makemake--pronounced something like McKay-McKay.* Makemake is slightly smaller than Pluto and orbits quite a bit further out. Makemake is another discovery by master planet finders Mike Brown and his team. This the same team that gave us Eris, Sedna, Quaoar, Orcus, and several others without official names.

Mike Brown has a habit of giving his discoveries whimsical temporary names. Eris was rather famously known as Xena while waiting for the IAU to take official action on its name in 2006. Another, 2003EL61 is called Santa by Brown and his crew. They called Makemake, EasterBunny. The latter two names came from Brown discovering them during different holiday seasons and adopting the icons of those seasons as easy to remember temporary names. Unfortunately, the naming rules of the IAU do not allow marketing mythology or television characters yet.** The IAU rules specify the area from which names are to be chosen, but allow the discoverer the right of nominating the actual name.

Brown explains his choice of Makemake like this:
Easterbunny has no obvious hook. Its surface is covered with large amounts of almost pure methane ice, which is scientifically fascinating, but really not easily relatable to terrestrial mythology. (For a while I was working on coming up with a name related to the oracles at Delphi: some people interpret the reported trance-like state of the oracles to be related to natural gas [methane] seeping out of the earth there. After some thought I decided this theme was just dumb.) Strike one.

I spent some time considering Easter and equinox related myths, as a tribute to the time of discovery. I was quite excited to learn about the pagan Eostre (or Oestre or Oster or many other names) after whom Easter is named, until I later realized that this mythology is perhaps mythological, and, more importantly, that an asteroid had already been named after this goddess hundreds of years ago. Strike two.

Finally I considered Rabbit gods, of which there are many. Native American lore is full of hares, but they usually have names such as "Hare" or, better, "Big Rabbit". I spent a while considering "Manabozho" an Algonquin rabbit trickster god, but I must admit, perhaps superficially, that the "Bozo" part at the end didn’t appeal to me. There are many other rabbit gods, but the names just didn’t speak to me. Strike three.


Suddenly, it dawned on me: the island of Rapa Nui. Why hadn’t I thought of this before? I wasn’t familiar with the mythology of the island so I had to look it up, and I found Make-make, the chief god, the creator of humanity, and the god of fertility. I am partial to fertility gods for things I discovered around that time. Eris, Makemake, and 2003 EL61 were all discovered as my wife was 3-6 months pregnant with our daughter. Makemake was the last of these discoveries. I have the distinct memory of feeling this fertile abundance pouring out of the entire universe. Makemake was part of that.

Oh, and Rapa Nui? It was first visited by Europeans on Easter Sunday 1722, precisely 283 years before the discovery of the Kuiper belt object now known as Makemake. Because of this first visit, the island is known in Spanish (it is a territory of Chile) as Isla de Pascua, but, around here, it is better known by its English name of Easter Island.

Now that the IAU has settled on the name plutoid for the group dwarf planets outside the orbit of Neptune, they will probably be naming one or two every time they meet for a while to come. For those keeping count, the official tally for our system is now four stony planets, four gas giants, four plutoids, around 180 moons, 1000 Kuiper belt objects, 3500 comets, and 10,000 asteroids with about seven more plutoid candidates under consideration and a few dozen believed to exist.

* This is going to be fun. Mike Brown initially announced that the proper pronunciation is maki-maki. It was only after this advice had gone out in news stories and been planted in Wikipedias of a number of languages that someone pointed out that the proper pronunciation should be MAH-kay MAH-kay. It will probably take years for that confusion to sort itself out. Meanwhile, in the spirit of Brown's previous plutoid, Eris, the goddess of discord, I'm doing my little bit to add to the confusion.

** When Herschel discovered the seventh planet, he suggested we call it George. If television names were allowed, we could have named the moons Jane, Judy, Elroy, Rosie, Astro, and Mr. Spacely.

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