backtop


Print 83 comment(s) - last by doctor sam ada.. on Jun 20 at 8:47 AM


Pluto and its biggest moon, Charon  (Source: NASA)
Pluto gets new classification: Plutoid

After being demoted from a planet to a dwarf planet by the International Astronomical Union (IAU) two years ago, the IAU has announced the term "plutoid" will be given to Pluto and similar dwarf planets.  Members of the IAU argued amongst themselves for two years, confused on how to classify dwarf stars like Pluto.  

Only dwarfs orbiting further than Neptune can be classified as a plutoid, and they must also circle the sun and be large enough to have their own gravitational field.  Pluto's permanent classification as a plutoid now means Neptune is the outermost planet in Earth's solar system; one complete orbit around the sun takes almost 165 years.

"Plutoids are celestial bodies in orbit around the sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit," said the IAU.

Pluto and Eris remain the only plutoids at the moment, but astronomers expect to find other small bodies that meet the qualifications to be a plutoid.

The controversy over Pluto's planet status has been strong for years, and the IAU-created plutoid classification most likely will not end the debate.  In fact, it is unlikely the debate regarding Pluto's status and what it should be classified as will never end, and defining it as a "plutoid" will only add fuel to the fire.

Many astronomers remain angry that Pluto, considered a planet for around 70 years, could have its status demoted so easily by the IAU.  Text book publishers and teachers must now begin to teach students that Pluto lost its planet status and is now a plutoid, along with describing the new classification.

The IAU has been the sole organization responsible for classifying all planetary bodies for more than a decade.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: But Wait;
By jbartabas on 6/13/2008 11:09:00 AM , Rating: 3
No, you missed the point.

Pluto is a dwarf planet whatever its orbit is. The same way, Ceres is a dwarf planet, even with its orbit well inside Neptune's.

Plutoid is just a sub-category of dwarf planets: the transneptunian ones. At best, you could argue that Pluto is not a Plutoid at times, but not that it's a planet.


RE: But Wait;
By phazers on 6/13/2008 3:03:55 PM , Rating: 2
>"Plutoid is just a sub-category of dwarf planets: the transneptunian ones. At best, you could argue that Pluto is not a Plutoid at times"

Clearly we need to spend trillions to fix this mess - fly out to Pluto, attach giant rocket boosters, and kick it out permanently past Neptune. This violation of the new planetary definitions simply cannot be tolerated by any intelligent species, or so the Plutonians tell me.


RE: But Wait;
By Ringold on 6/13/2008 5:41:31 PM , Rating: 2
quote:
Plutoid is just a sub-category of dwarf planets: the transneptunian ones.


Others seem to still be fighting the planet label battle, but this is the part I see as stupid. It seems obvious to me; IAU wanted some positive PR for the unwashed masses, and thus battled for 2 years to get a special label just for ol' Pluto.

Their first mistake: The unwashed masses dont really care. Just geeks, but they got over it. This just reopens the issue.

Their second mistake: Never appease the unwashed masses.

I see the posts claiming its just a nice measure in creating further categories; whatever smoke screen makes the IAU feel good. Dwarf planet got the job done. It's shameless pandering. Considering it took them 2 years to get it done, sounds like some astronomers would agree.

I think, perhaps, they should've drawn the line at the frost line; isn't that just a wee bit past the asteroid belt? Then they could've distinguished between ice and solid planets, perhaps. But Neptune? Purely arbitrary, and with Pluto only being a Plutoid part-time, it shows.


"I'm an Internet expert too. It's all right to wire the industrial zone only, but there are many problems if other regions of the North are wired." -- North Korean Supreme Commander Kim Jong-il











botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki