By next month our Solar System is expected to officially contain twelve planets, meaning astronomy texts and astrological charts will have to be republished. The new lineup in order from the sun will now be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto/Charon and 2003 UB313 (nicknamed Xena).
The International Astronomical Union has long been accepted globally as the authorized arbitrator of all things planetary since 1919. The IAU’s Planet Definition Committee (PDC) seven-expert committee is made up of various experts ranging from historians to astronomers. They assembled in Paris this June and July to hear and settle on proposals that were then sent to the International Astronomical Union’s general assembly in Prague convening August 14 through August 25.
The meeting was called as a result of a long-standing fight over whether Pluto is actually a planet or not. The Hubble Space Telescope and other ground based observers have found objects in our solar system that are larger than our most distant orbital cousin. The discussion came to a two-year head just recently, with the discovery of UB313 (nicknamed Xena for now) which will be officially named later. The new planet is beyond Pluto and is larger and has a single moon.
The question was whether to declare UB313 the tenth planet in our solar system or downgrade Pluto. Pluto was originally given planet status in 1930 when it was thought to be as large as Earth. With Pluto’s moon Charon being similar in size to its neighbor, Pluto/Charon is now expected to be classified as a “double planet” because they’ve been found to more or less revolve around each other.
IAU Resolution 5 for GA-XXVI: "A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."
The IAU also drafted a resolution to define a new subcategory for planets called a "Pluton". Plutons must take more than 200 years to complete an orbit or must reside beyond Neptune. This would include Pluto, Charon and “Xena”. The new system could cause havoc with astronomers as local celestial bodies are being constantly discovered beyond Pluto’s orbit that will meet the criteria.
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Article comments
— go to most recent comments1 - Jet in Columbus
Thanks Lisa, and thanks for putting up with me...
Jet
2 - JustOneMan
Lets not forget the signiciant politcal implications of this! As reported on riehlworldview.com
The solar system shaking news is said to have kicked the political strategy of Governor Mark Warner into hyper-orbit as Warner strategist Jerome Armstrong aka poli-strologer vis numar re-calibrates his thinking to accommodate the potential new additions to our planetary system.
As for Armstrong himself, he suggests this is obviously why the bulk of his political prognostications proved to be so far off the mark. "I simply couldn't see all the little buggers from down here," said Armstrong.
3 - Jet in Columbus
JOM-was that really necessary? This is one of the most important Astronomical decisions to be made in 80 years.
4 - duane
It might confound astrologers, but why does it delight astronomers? And confound those astrologers anyway.
5 - Jet in Columbus
Astrologers now have to recalibrate their charts to make way for planets in astrological houses that didn't exist before.
Astronomers like my self are delighted with any news of this calibur.
How often in a lifetime is something like this announced?
Carus deus, quis have ego commissio?
Jet
6 - duane
Not to quibble, Jet, but the important thing is that the celestial bodies were discovered in the first place, not what they're called. It's kind of like if biologists decided to change the name of mitochondria to lypochondria or something. It doesn't change the nature of the specimen. The line is still somewhat arbitrary, since it leaves open the issue of deciding what is spherical enough. It's like if I decided that only people over 6' 3" should be referred to as "tall. "
7 - Jet in Columbus
So what you're saying other than to argue symantics is that you really enjoyed the article. Thank you Duane.
8 - duane
Well, yes, Jet, I did enjoy the article. And I won't argue with you if it bothers you (but I am right).
9 - Jet in Columbus
I have never been afraid to admit I was wrong. Now back to the article?
10 - Deano
My only hope is that they find a better name for 2003 UB313. As much as I like Lucy Lawless, naming a planet Xena just seems silly...
11 - Jet in Columbus
Deano if you think about it, it's as good as any really
Carus deus, quis have ego commissio?
Jet
12 - RJ Elliott
Ceres is not a planet...it is just a big-ass piece of garbage from the Asteroid Belt.
Pluto is not a planet...it is just a relatively-large piece of non-round trash from the Oort Cloud/Kuiper Belt.
Charon is not a planet...it is just a satellite of non-planet Pluto.
And "Xena" is just an incredibly-distant chunk of frozen shit.
There are 8 planets...EIGHT! And anyone who disagrees with that is some sort of un-American atheist commie pinko... ;-/
13 - Dileep Saxena
7000 years ago history of Indian Astrologrs have already confirmed the the present theory of 12 (RASHI GRAH) planets. and they were predicting the present past and future based on 12 planets theory. I think it has to be corelated with that for the future better prospects.
14 - duane
Aw, that's nothing. Forty thousand years ago (give or take a few days), Og, of the Sabre-Killer Clan, who were settled in what is now the Nivernais Province of France, predicted 12 planets. Damn French.
15 - Ruvy in Jerusalem
You can take up the astrological issues with the house astrologer at BC, Duane. What I'm curious to know is if anything beyond "Xena" has been found... A big planet about 3 to 5 times the size of earth with a really wierd 3600 year orbit....
16 - Ruvy in Jerusalem
@ #14...I see that someone reads Jean Auel...
17 - Jet in Columbus
RJ 12...Too much caffeine this morning?
18 - Jet in Columbus
Dileep #13-Well possibly for this exact mooment, but it's already been said that several objects larger than Xena have been detected but not confirmed so the total would be higher...was that predicted?
19 - Jet in Columbus
Ruvy-15, yes that eiilusive planet has been hypothosized a few times. The problem is that it appears to be made of some dark material which doesn't seem to reflect much light and only appears when it transits another known star at a predicted time.
It'd certainly explain the amount of mass that seems to be missing in the solar system.
Either that or it's a Dyson's Spehere
Jet
20 - Clavos
#19. You just described a Black Hole.
21 - Deano
My objection to Xena is not related to the TV show (which, in it's strange quasi-lesbian ethos, is rather fun to watch) but that as a planetary name it doesn't have the same ring or meaning behind it as does, for example, a Charon (ferryman to the underworld).
While does it inspires illicit thoughts of Lucy Lawless in a leather studded bustier, it doesn't have any real poetry inherent in its name.
22 - Jet in Columbus
Clavos for a moment I thought you were commenting on the Maurice Clarett story by mistake... my bad
23 - Deano
By the way the speculation among astronomers is that the sun may have a companion star deemed Nemesis. This is also sometimes referred to as the 10th planet.
Nemesis is a hypothetical red dwarf star or brown dwarf, orbiting the Sun at a distance of about 50,000 to 100,000 AU, beyond the Oort Cloud. It's orbital path has been speculated to be responsible for the intermittant 25-million year extinctions on Earth, supposedly due to the flood of comets who's orbits get altered when it swings past the Oort Cloud periodically.
Nemesis, by the way is a pretty cool name - she was the goddess of divine retribution.
24 - Jet in Columbus
I agree Deano, but the thing has been referred to as Xena for so long, it just might be inevitible.
Is there a greek god for the misnamed?
Tantum meus sententia
Jet
25 - Victor Plenty
Pluto was so named because it was thought to be the farthest distant from the sun. Now we know it isn't, so we should name it something else. The planet now called Xena can then be called Pluto, until we discover the next one farther out, and then we can keep shifting the name each time our detection limit expands.
On a more serious note, much of the resistance to formally defining the term "planet" arose from the fact that the proposed definition might easily lead to an eventual listing of 50, 100, or even more objects classified as planets.
I don't have trouble with that possibility myself, but apparently many people are thinking of the children (who already have difficulty memorizing the names of just 9 planets, even though their minds seem to have plenty of room for indefinite numbers of Pokemon subspecies).
And of course then there's the other problem we're already bumping up against, which is that the Greeks and the Romans had only so many gods.