Tuesday, September 29, 2009

NASA: Xena is bigger than Pluto, Quaoar and Sedna


Quaoar?  Sedna? We already knew about Pluto, once regarded as the ninth planet in our Solar System.  But Pluto was demoted from planet to "object" not long ago, and placed in the club of other Kuiper Belt Objects.

It's not easy to remember that Quaoar and Sedna are Kuiper Belt cousins to such objects as 2003 EL61, an ovoid planetoid with a name like a vacuum tube, let alone pronounce their names.  I'm struggling with Quaoar and am sure that I sprained my tongue. I imagine Quaoar might be more popular in some country such as Saudi Arabia, since they are already near Qatar, which is also unpronounceable in Massachusetts. 

Kuiper, I think, is supposed to sound like "wiper" with a K, but maybe not.

Say it like this:  Qwaaaaooooorrrrrrrr !  Sedna is easy, but weird.  Xena, of course, is the Warrior Princess.

2 comments:

Laurel Kornfeld said...

Please do not blindly accept the demotion of Pluto by only four percent of the IAU, most of whom are not planetary scientists. Pluto is still a planet in our solar system, but it is the 10th rather than the 9th. Hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA's New Horizons mission to Pluto, signed a formal petition rejecting the IAU planet definition. They favor a broader alternative definition in which a planet is any non-self-luminous spheroidal body orbiting a star. The spherical part is important because objects become spherical when they are large enough to be shaped by their own gravity, a state known as hydrostatic equilibrium. This is a characteristic of planets and not of shapeless asteroids. Using this definition, our solar system has 13planets and counting: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris. If Quaoar and Sedna are found to be in hydrostatic equilibrium, they should be counted as planets as well. Pluto, Haumea, Makemake, Eris, and potentially more objects such as Quaoar and Sedna are BOTH planets and Kuiper Belt Objects.

Anonymous said...

I have become large enough to be shaped by my own hydrostatic equilibrium. The spherical aspect is becoming apparent.