Xena, Pluto, the Hubble Telescope and the scientific community

Demote Pluto and Kill Xena
Author Robert Roy Britt
A press release today from the good folks who operate the Hubble Space Telescope contained 13 mentions of “Xena,” an unofficial term given to a Pluto-sized world that its discoverer hopes will be called the 10th planet. The object is smaller than first thought. It’s also less significant than some argue.
The world is not “Xena.” Officially, it is 2003 UB313.
But discoverer Mike Brown of Caltech is on a mission to have 2003 UB313 declared a planet, so he gave it a catchy nickname.
Other astronomers, and the good folks at Hubble, should not use the nickname. What they should do is finally agree on a definition for the word “planet.” And 2003 UB313 should not be included.
The reasons are simple. Even Mike Brown says there is no scientific basis for calling 2003 UB313 a planet. Here is what he said last year:
I will not argue that it is a scientific planet, because there is no good scientific definition which fits our solar system and our culture, and I have decided to let culture win this one.
If scientific decisions are to be henceforth based on the whim of culture, it is time for astronomers to pack up their telescopes and go back to dreaming up stick figures out of random star patterns. And while we’re at it, perhaps we should consult religious leaders for their opinions on how to interpret the results of astronomical observations.
At any rate, it is not Mike Brown’s place to decide this. The International Astronomical Union governs nomenclature in astronomy.
The problem all started when Pluto was discovered in 1930 and called a planet. That was a mistake that astronomers only realized later. Diminutive Pluto’s orbit, like that of 2003 UB313, is way out of whack with the main plane in which the other eight planets roam. And we now know there are a handful of other offbeat worlds almost as large as Pluto. Estimates suggest there are hundreds of Pluto-sized worlds out there waiting to be spotted.
If 2003 UB313 gains planet status, we’ll instantly have so many planets that kids won’t be able to memorize them all. Worse, the list will be a lie, made up of eight bona-fide planets and dozens of compounded mistakes. That’s not science.
The solution is simple. It is high time astronomers stop arguing minor details and come together to hammer out a definition. One distinction should be clear:
Objects like Pluto and 2003 UB313 should be called minor planets or dwarf planets or something else that denotes their relative insignificance compared to the four inner terrestrial planets and the four outer giants. And therein lies the precedent: We already have terrestrials and giants. Just add dwarfs.
School children will initially rally and astronomers will get angry emails (just ask Neil Tyson). But science will have done the right thing and everybody will get an education about the makeup of Our New Solar System, a place packed with a much wider variety of objects than anyone dreamed of just a few decades ago.
Is it really that hard for astronomers to be honest, scientific and accurate?
Meanwhile, those who write press releases and journalists who cover all this should stop using the nickname “Xena” to describe 2003 UB313. Only when a proper definition for “planet” has been agreed on by the International Astronomical Union can astronomers decide on a name for the tiny, way-out world.
This entry was posted on Tuesday, April 11th, 2006 at 1:53 pm and is filed under Space & Astronomy. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

My reply:

The real reason for arguing so much about the planethood of Pluto and other space objects is about keeping the historic solar system textbook in place. It feels good to know that there are only four terrestrial planets and four gas planets to mention in this textbook.

However, I wonder how we could reconcile the facts that both groups are essentially different (rocky objects vs. gas objects) but are both called "planets". Is the ongoing technological revolution- leading to KBOs discoveries - giving us a headache because we can't accept the diversity of the solar system?

Even if there were hundreds or evem thousands of KBOs bigger than Pluto, I would not change my position, they need to be called "planets".

Sailom