[meteorite-list] 'Plutons' Push Planet Total Up To 12

From: Larry Lebofsky <lebofsky_at_meteoritecentral.com>
Date: Wed Aug 16 06:45:49 2006
Message-ID: <1155725144.44e2f7589719c_at_hindmost.LPL.Arizona.EDU>

Hi Sterling:

Yes, Sterling, Ceres is a planet (if this passes the General Assembly). With
respect to Ceres being a carbonaceous chondrite this comparison has been made
since the early 80s. Google my name and Ceres and there are many hits for
water on Ceres.

Larry



Quoting "Sterling K. Webb" <sterling_k_webb_at_sbcglobal.net>:

> Hi,
>
>
> Yes, Ceres is a planet again... if a vote of the whole is in favor!
> I predict a cantankerous electorate on August 24th! Ceres was a
> planet officially from 1804 to 1864, In 1855, the Big Four were
> retained as planets but all the others were demoted to minor planets.
> In the US, Ceres continued to be mentioned as a planet up into
> the 1870's.
>
> All planets have official planet symbols, you know. We've
> all seen them; they're on jewelry even. Is there a market for
> a new symbol for the new planets (if they vote'em into the
> club)? Well, Ceres, Vesta, Pallas, and Juno already have
> symbols from back when they were planets the other time.
> Good old Naval Observatory has 'em:
> http://aa.usno.navy.mil/hilton/AsteroidHistory/minorplanets.html
>
> But "Xena" and the other qualifying crutons, er, plutons
> don't. Probably have to wait until they have names...
>
> Ceres and the rest of the Big Four, even in 1864, were
> thought to be much larger than they really are. "At the time...
> the most widely disseminated values for the diameters of
> the first four asteroids discovered were Ceres, 2613 km
> (really 975x909); Pallas, 3380 km (really 570x525x500);
> Juno, 2290 km (really 290x240x190); and Vesta (really
> 578x560x458), not more than 383 km." Well, they were
> close on Vesta... You'll notice that only Ceres is really
> ROUND enough...
>
> Ceres density 2.08. Pluto density 2.03. Both densities are
> most easily modeled by a 50-50 mixture of ice 1.0 and rock 3.0,
> or some quibbly variation thereof. However, Ceres is darker
> (albedo 0.113 versus 0.50). There are signs Ceres has a transient
> atmosphere like Pluto. Ceres appears to have complex organic
> chemistry, so it may be the solar system's largest carbonaceous
> chondrite!
> http://www-
ssc.igpp.ucla.edu/dawn/newsletter/html/20030822/ceres_evolution.html
>
> The DAWN mission will get to Vesta October 2011
> and reach Ceres February 2015. Both Vesta and Ceres
> will be full-surface mapped. DAWN will carry two LDR
> LEON2 chip framing cameras as described below:
> http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=DAWN&ex=1
>
> The resolution on the low-orbit passes will be a sharp
> 5 meters per pixel, roughly comparable to the Mars HiRISE
> camera. It'll be stupendous. I really hope I live until 2015.
>
> Brian Marsden, in the article below:
> <http://www.space.com/scienceastronomy/050802_planet_definition.html>
> is quoted as saying if the Allan Stern definition of a planet
> were used (everything spherical that goes 'round its star
> and doesn't fusion inside), we'd have 24 planets.
> Marsden wasn't in favor of the Stern definition, and
> it appears that the Stern definition is pretty much what
> the IAU Committee submitted for a vote.
> But, the way they're putting it forward is that Pluto
> stays, Ceres gets planet status (again), 2003UB313
> is a planet and Brown gets to apply for a planet name.
> Now, there's a moment in an astronomer's life!
>
> I think Marsden was exaggerating (he's in charge
> of non-planets and the shepperd could lose some sheep)
> when he said 24. Stern says 20... Let's start counting.
>
> Ceres is Planet 5. Jupiter, Saturn, Uranus, Neptune
> all get their numbers bumped up one. Pluto, the "nineth"
> planet (might be) is now Planet X (for Ten) and Charon
> is Planet 11. If we add 2003UB313 ("Xena"), 2003FY9,
> 2003EL61, Sedna, and Quaoar we have 16 planets.
> Now, can everybody spell Q U A O A R ?
> Can ANYBODY say it?
>
> Whoops! We have to add 90482 Orcus; it's bigger
> than Quaoar. That makes 17 planets. There are five
> more KBO's for which a case could be made, except
> that circularity might be a problem; they're smaller and
> could be irregular. That would be 22 planets. Or 24.
> Or 20. Schoolchildren are going hate us! 17 planets to
> memorize ("Do I gotta?!") AND learn how to spell
> QUAOAR?
>
> Somebody is sure to get offensive about 2003EL61
> just because it isn't round. I think we need an exception
> for dynamic distortion. Yeah, true 2003EL61 is about
> 1960 x 1520 x 1000 km. Not very round. OK, it had this
> really rough childhood, see... But its density is almost
> as great as the Earth's Moon! This is no iceball! It's
> solid rock. It rotates in 4 hours; it's dynamically distorted,
> So is Jupiter and all other rotating bodies. Even I have a mild
> equatorial bulge and I'm not spinning at all.
>
>
> Sterling K. Webb
> ---------------------------------------------------------------------
> ----- Original Message -----
> From: "Darren Garrison" <cynapse_at_charter.net>
> To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
> Sent: Tuesday, August 15, 2006 11:17 PM
> Subject: Re: [meteorite-list] 'Plutons' Push Planet Total Up To 12
>
>
> On Tue, 15 Aug 2006 23:04:18 -0500, you wrote:
>
> > Spoze he meant CHIRON?
>
> Naming a drug company as a planet would be even more of a problem. What
> would
> be next, planet Eily Lilly?
>
> On a more serious note, the article mentions Ceres. I'm not clear on this,
> were
> they saying that Ceres would be given planet status? Surely it wouldn't be
> lumped in as a cruton... I mean Pluton?
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-- 
Dr. Larry A. Lebofsky
Senior Research Scientist
Co-editor, Meteorite                      "If you give a man a fish,   
Lunar and Planetary Laboratory               you feed him for a day.
1541 East University                       If you teach a man to fish,
University of Arizona                        you feed him for a lifetime."
Tucson, AZ 85721-0063                                     ~Chinese Proverb
Phone:  520-621-6947
FAX:    520-621-8364
e-mail: lebofsky_at_lpl.arizona.edu

Received on Wed 16 Aug 2006 06:45:44 AM PDT