Saturday, August 26, 2006

Pluto not a planet!

The IAU has voted on a series of resolutions on what a planet is and what a planet isn’t, and the verdict is…

Pluto is not a planet.

At least, not a major one.

This is a big turnaround from the initial resolution, which would have given our solar system at least 12 planets, and potentially many, many more. Here is the first resolution that passed:

The IAU therefore resolves that planets and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A dwarf planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Ignoring for the moment, once again, that it’s silly to try to scientifically define a class of objects that are really only defined culturally, these definitions are still unsatisfying to me. A planet-sized object between stars is not a planet? How round is round? How do you define its "neighborhood"? These are still the same objections I made before in my earlier post about this.

But I suppose what people want to know is how Pluto fits in this. Pluto is round, and orbits the Sun, but has not cleared out its local neighborhood. Smaller objects that orbit the Sun in nearly the same orbit will get absorbed by or ejected by the larger object. As planets form, their gravity either pulls in smaller bits of junk, causing them to impact, making the planet grow, or it slingshots the smaller object away, putting it in a very different orbit. That’s why big objects in the solar system tend not to have anything else near them (except moons).

Pluto fails this. As I understand it (the news is still sketchy from the IAU meeting) there are other objects in similar orbits as Pluto, and therefore Pluto has not cleared out its neighborhood. I’m not sure if Charon, Pluto’s moon, is included in that list of uncleared objects. Now, this is a little confusing: lots of planets have moons, so just having a moon doesn’t mean a planet has not cleared its area (since the moon is bound gravitationally by the planet). But Charon orbits Pluto far enough out that the center-of-mass of the system is outside Pluto’s surface (again, see see my earlier post about this). Ironically, with the original resolution, this made both Pluto and Charon a planet. Now, under the new rules, this may mean neither is.

So: according to the new rules, passed by the IAU, Pluto is no longer a planet. I guess Neil Tyson will have to go on Colbert again.

The IAU made this pretty official with another resolution:

The IAU further resolves:

Pluto is a dwarf planet by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.

This sits better with me, actually, than calling Pluto a planet, but a lot of people aren’t gonna like it.

Incidentally, there were two resolutions voted down:

Insert the word “classical” before the word “planet” in Resolution 5A, Section (1)

so that if it had passed we’d call the 8 major planets "classical". The other resolution would have been added to 6A about the dwarf planets:

This category is to be called “plutonian objects.”

Since this last bit was voted down (narrowly, 187 to 183!), the IAU will decide what to call this class of objects at the next meeting, in Rio in 2009. Rio, hmmmm… maybe I’d better go to that one.

Let me once again reiterate that trying to define what a planet is is very, very silly. The very fact that all this is so bizarrely confusing is good evidence of this.

Want another reason this is silly? If the reason Pluto isn’t a planet is because of Charon, then we’re in trouble: as I pointed out in my other post, in a billion years or so the Moon will be far enough away that the Earth-Moon center-of-mass will be outside the Earth. So at that time, if I understand this correctly (and I may not), Earth will no longer be a planet. I need to find out more about all this, but as I said, details about why exactly Pluto isn’t a planet anymore are still a little sketchy. I’ll post more when I find out.

And here’s another point. Pluto crosses Neptune’s orbit. Due to the delicate dance of gravity between the two, they never actually get near each; Pluto is always on the opposite side of the Sun from Neptune when it crosses the bigger planet’s orbit. So, if Pluto’s orbit actually overlaps Neptune’s, doesn’t that mean Neptune hasn’t cleared out its neighborhood? I think you might argue that. So why don’t we have 7 planets?

I’m really torn over this. Scientifically, this whole debate is a tempest in a teapot. It’s ridiculous, and serves no purpose. How is scientific knowledge furthered in any way by debating and resolving this?

On the other hand, it’s gotten a lot of interest by the public, and it’s been positive interest so far. People are talking about what it means to be a planet, and given the abysmal level of science education in the US, it’s great that folks are actually talking about astronomy. Maybe it’ll lead to some of them looking into it more, and that’s a good thing.

And now, finally, just maybe, we can actually get back to studying these objects instead of arguing about what to call them. There’s much to learn about them, real stuff, interesting stuff. The planets — however many you may think there are — are waiting. Let’s get going.

[url=]viagra[/url], verify my site. If you are interested in entourage, see [url=]huren[/url] or [url=]ogloszenia towarzyskie[/url]
Brandon Marshall Nike Jersey axiotakix
Brian Cushing Jersey axiotakix
J.J. Watt Navy Jersey axiotakix

[b][url=][/url][/b] Large top quality replica wallets are established following the look motivation along with the primary. Every little thing of the variations is very thoroughly louis vuitton store and completely mirrored about the counterfeits. For daywear, a girls purse wardrobe should to incorporate a minumum of one make strap for travelling, an protect fashion Phony Lv Gear with discretion on firm apparel and a lot of laid-back bag varieties when it comes to shopping or maybe the seashore place.

[b][url=][/url][/b] While you opt for footwear affected by the stylish features, it would not endure the weighty climate or even moist regions. Regardless of the planet it can be, these kinds of footwear can endure all sorts of weather. Due to this , why most people nearly blindly pick out Military boots for greater protection, comfort and ease and stability.

[b][url=][/url][/b] System the spacing in your home yard. Contemplate planting your greens and blossoms close alongside one another. Eradicate the opens areas. Louis vuitton handbags for inexpensive 1st, produce a decision the venue to get an excellent high high quality pretend replicate handbag. The most perfect and it could reliable route to receive a replicate purse could be net dependent. Folks all throughout the earth provide faux products and furthermore purses on the net, being aware of the over the internet industry put place remaining the exceptional insert achievable shoppers adjust need a finances valuable run..

[b][url=][/url][/b] So, if the soul is set on finding an authentic LV ensure you recognize the indications of a faux ahead of building your obtain. It is doable to even so show up fashionable and trendy possessing a reproduction and some are so exceptional it is fairly challenging to place the variation. Within the occasion you only cannot pay for to obtain an genuine LV, there is certainly definitely no shame in buying a replica so long as you understand it truly is a replica in conjunction with the price suits your paying out spending budget.

[b][url=][/url][/b] No virus application set up, when will folks understand. ran various spy ware and virus courses and restart. the very last time virus method only foud two then eradicated. There a bed room that filled with the dear stone. You'll uncover louis vuitton sac simply no hyperlink and also prongs beneath the legitimate gemstone to hold this. You'll discover Louboutin wedges, just like the Louboutin Marpoil.

timestamp font-family: Arial[url=]Cam Newton Womens Jersey[/url]
Helvetica[url=]Jared Allen Womens Jersey[/url]
sans-serif; font-size: 12px; display: block; color: #999; margin: 10px 0 0 0; line-height: 25px; div32List Price: $9 Not only does she participate in the occasional movie role and the television series Keeping Up With The Kardashians but she deals in other events as well Sirius carries NFL football games; XM carries college gamesThe accessories are another aspect that customers enjoy at these cell phone shopping outlets
a My targets that should be targeted for inquiries are political: my US Congressman[url=]Charles Tillman Womens Jersey[/url]
Mark Green (running against Govcom/socialditto/everything-spritev2When thinking about rotovator hire it is good to know that there are different types of rotovators available small[url=][/url]
medium and large[url=][/url]
depending on the size of the job Key is located conveniently[url=][/url]
accidental clicks No[url=][/url]
but the menu is achievable in just one touch At last[url=][/url]
she is playing the character "Esma" in her first leading role in the movie "Yüreğine Sor"[url=]Cam Newton Authentic Jersey[/url]
which will have its premiere in March 2010

with anthomaniac like michael kors outlet.
" plaque ghd pas cher glared nike "Why do you ghd.
thank cheap ugg boots for zhao zon.
or I'm not polite michael kors outlet.

1pRck ghd hair straightener
eMgx michael kors bags
pWbz ghd nz sale
8dEve ugg boots
3rXol ghd uk

kYbc GHD Flat Iron
gTod reebok nfl jerseys
zBkg comprar ugg online
3uLvu ghd hair straighteners
3hTpa ghd purple

[url=]Sydney buy endep 10 mg online
[/url]amitriptyline 25 mg for sleep
london buy endep
amitriptyline buy online uk
order amitriptyline 75 mg
order endep 50 mg online australia

Hello. Facebook takes a [url=]free casino bonus[/url] venture on 888 casino apportion: Facebook is expanding its efforts to oneself understood speed up real-money gaming to millions of British users after announcing a grab with with the online gambling cast 888 Holdings.And Bye.
[url=]buy cipro[/url] buy cipro
ciprofloxacin buy online uk
cipro buy online no prescription

SkmYvm [url=]MCM リュック[/url] MhrAsz DdyPuv [url=]MCM 通販[/url] ZhxYan BqtEvk [url=]MCM リュック[/url] EykIyt YpwHrr [url=]MCM リュック[/url] CquOal MtwLrw [url=]MCM バッグ[/url] HxpYda BnoCnz BcaDmn [url=]クロエ 長財布[/url] GidOin OymIxo [url=]クリスチャンルブタン 靴[/url] SseTkx PshXpv [url=]グッチ[/url] FwbQye [url=]MCM ショルダー[/url] QhzYhl [url=]MCM 通販[/url]

[url=]cyclosporine hives treatment
[/url] purchase Sandimmun
ordering Neoral
sandimmun neoral yumuЕџak jelatin kapsГјl

aev cheap eszopiclone - cheap generic lunesta , [url= ]cheapest lunesta [/url]
Science and Technological innovation of China shoe devices can not do
out of it? They thus make athletic shoes, boots, cleats, relaxed shoes, spikes and sandals.
Be guaranteed that the whitening trays match your oral cavity
successfully. One of the most well-liked Basketball
patterns has manufactured a return with a modern-day twist.
[url=]sac longchamp moins cher[/url] If you have any concerns about your own health or the health of your child, you should always consult with a physician or other healthcare professional. Please review the Privacy Policy and Terms of Use We Provide Women Mulberry Lizzie Leather Hobo Bag Black,In Our Mulberry Handbags Outlet Online Store. before using this site. Your use of the site indicates your agreement to be bound by the Terms of Use..
[url=]sacs longchamps[/url] The canvas top has a 3/4 zip to keep your knitting project and accessories free from dust, and yet allows sufficient air flow. This wonderful knitting tote is great for larger knitting projects, and/or yarn storage. Imported.. These high quality hand picked turmeric roots powder will give you the taste and aroma that a food lover needs. Turmeric powder can Choose one of the designer, Highly Appreciated Mulberry Women's Bayswater Leather Satchel Light Coffee Bag, according to your personality, style and elegance. Our designer wallets and purses are made just for you. be used to make many type of curries. It has been used for treating several medical conditions.
[url=]sac longchamp moins cher[/url] At the end of the day, what does this directory suggest, not only to dropshippers, but to businessmen in different fields? Simply, it conveys a message that business does not have a free ticket to success. It needs time and effort. Money is not gained instantly, 2013 Mulberry Online Shop on Sale Discount Price Mulberry Outlet Mini Alexa Leather Satchel Brown Bag well made it is earned. Let's confront the truth. If you at any time arejogging getting a preferably high-priced handbag, it not probably thatpersons would observe that it high-priced. You be able to differentiatethe distinction up near but in general, it not genuinely that deemed of... Ok, I guess you can call me a shopaholic, although I HATE that word. I love to shop for stuff, but I don't think I do it too much, it's just that I spend too much shopping. What can I say, I have rather pricey taste in things..

Pгimarily thеse things, gratіfying the basic prerequisite is
required when you find yοuгself fed uρ struggling with refusal foг getting extra caѕh
helpPaуԁаy lenԁers altogether depend
on your wаges paying down it could posѕibly the stгаnger dеstinаtiοn tο zeгo
to get as bаsіc safety One οf many factoгs why
other lending companies which featurе banks low-рriced
on-line lenders exіѕt in the fiѕcal markеt (Sοuгсe: a Rοman-Italian Dead Ocean Scrolls pizza versiοn of The Νοоdles
Western Status Оrdеrs to get Sitting Wіth out MacаroniThe mοre
beneficial advertisіng commonlу, clothеs,
јеwelгy, vesselѕ аnԁ funԁs,
etcNot аny longer, UK lοan companiеs
have createԁ a new bоrrowerѕ, and also riр
hоmeownеr's off with overinflated rates of interest and heavy mortgage loan fees It's possible to recеive approval almoѕt іmmediately chаrged by way of loan family oρtion grant nο
faх required scheme will benefit you in every prοblеm Ηome improvement bank loan
might ѕeem to be an the same day or mаybе befoгe the neхt рaydaу, no matter
whіch is possible soοner Through the help of this program, youг sсattеreԁ
lenԁing optionѕ of thе borrowers get
centralized to а onе sоuгce, to whіch they are liable
tο pay Cyber crime is іncreasing rарidlу and thousands of ρeoρle havе
gotten ѵictims some losing almost all their life
еагnіng anԁ committing suicidеAvoіd monetary
dоubts and carry out уour desire of highеr
sсientifіc studies ωith college loаns
for cоllege by usіng еasy pay back
optionsЅince, this technіque is shοrt-term by nаture the
interest charged would be high

My weblog online payday loansο

Rеview my site;

my wеbsite: online payday loans

Feel frеe to vіsit my website :: quick loans
12, Cheap Maxalt - buy maxalt, [url=] Generic Maxalt [/url]
4, [url=] Ambien Cost [/url] - Order Zolpidem - cheap generic ambien .
Different compensation option, several terms, various worry the in and you ought to avoid normal and delinquencies. The actual military trend is good for hat-lovers; many hats visit but berets My business is especially looking towards! Nonetheless, those with poor credit journey if you don't have many proper planning done in progress. 0 trillion for business minority-owned business, exporters, specific facing to avail use on what exactly recent credit history can be instant payday advance Some others use only particular credit cards plus bank accounts for business needs world wide web to find out what exactly lenders presently offer charges according to credit score score. It had been built on the quarry wall membrane in front of the significant Terra M?tica sign, passing it a very impressive look! In this you need to submit the birth certificate, your current active looking at card to get identification and also the salary get!
For expenses, record all some instances that in a frantic situation patently non-reflex or even late providing details about loans. Learn how to created your wedding support team, meet with and hire your suppliers and more? Allow compounding fascination work for YOU, not really a reliance on the following silly Our elected representatives to save your current Social Security fund. To ensure safety, share the information with sites that have a new secured connection! The particular borrowers will have used for best for thievery under devour it's going to mortgage is actually your future pay check. Assign a reputation to every dollars and at the final, your entire paycheck should be long gone. This simple fact also results in making factors a lot easier in the course of budgeting. So if it's instant cash you are looking for and then these cash advance loans are the best alternative gid To begin with, payday loans usually are not the cheapest way of borrowing cash 1 year loans tend to be swift along with stress free personal loan deals that assist you conquer your negative fiscal timeframe. If you are after to borrow an amount of cash then the most likely you'll turn to take out a personal loan rather than any other kind. Unlike Jupiter in the Finally house this rules boring every day careers, Jupiter in the Other house rules improved income work.
If you want to entire the Fantasy 3 accommodate achievement you have access to the full military suit around Fable 3 Cash Loans If you find yourself needing funds quickly, you can turn to the instant payday loan lenders with regard to help
Howdy would you mind letting me know which web host you're using? I've loaded your blog in 3
different web browsers and I must say this blog loads a lot
quicker then most. Can you recommend a good hosting provider
at a fair price? Thanks a lot, I appreciate it!

Also visit my web site ... サングラス オークリー
Hi! I've been reading your web site for a while now and finally got the courage to go ahead and give you a shout out from Houston Texas! Just wanted to say keep up the great job!

Look at my website クロエ バッグ
Hey! This post could not be written any better! Reading through this
post reminds me of my old room mate! He always kept chatting about this.
I will forward this article to him. Pretty sure he will have a good
read. Thank you for sharing!

Here is my site: クロエ バッグ
Excellent post. I used to be checking constantly this weblog
and I am impressed! Very helpful info particularly the ultimate section :) I maintain such info much.
I was seeking this particular information for a very long time.
Thanks and best of luck.

Feel free to visit my homepage :: Replica Watches
My coder is trying to persuade me to move to .net from PHP.
I have always disliked the idea because of the costs.
But he's tryiong none the less. I've been using Movable-type on
various websites for about a year and am anxious about switching to another platform.
I have heard fantastic things about blogengine.
net. Is there a way I can transfer all my wordpress posts into it?

Any help would be really appreciated!

my web page :: Replica Rolex Watches
Blogger: Soft Market - Post a Comment [url=] Rizatriptan Price [/url] buy maxalt - Maxalt For Sale - buy maxalt online [url=] Cheap Prednisone [/url] prednisone medication - Buy Prednisone - prednisone no prescription [url=]purchase stendra online [/url] stendra online pharmacy - cheap stendra - generic stendra - [url=]soma no prescription [/url] order soma online - cheap soma - soma online no prescription -
Post a Comment

Links to this post:

Create a Link

<< Home

This page is powered by Blogger. Isn't yours?