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FireFox Snowy Owl


Joined: Feb 18, 2008 Age: 20 Posts: 157
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Posted: Fri Jun 27, 2008 8:18 pm Post subject: Pluto is no longer a planet. |
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| They've changed it's status to a dwarf planet. They did this back in August of 2006. What are your thoughts on that? The Solar System has only eight planets in the new classification. Pluto is a dwarf planet along with Eris and Ceres. |
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Rainbow-Squirrel Phoenix


Joined: Dec 27, 2006 Age: 28 Posts: 974 Location: Siena, Italy
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Posted: Fri Jun 27, 2008 8:21 pm Post subject: |
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| I LOVE the name "Pluto"... |
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Reodor_Felgen Counting down till Castro bites the dust

Joined: Sep 29, 2007 Age: 19 Posts: 1475 Location: Norway
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Posted: Fri Jun 27, 2008 8:26 pm Post subject: |
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I wish they would let Pluto be a planet. Eris should also be classified as a planet, but Ceres shoul be classified as an asteroid. _________________ "The urge to save humanity is almost always only a false-face for the urge to rule it."--H. L. Mencken |
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twoshots Honorary Vertebrate

Joined: Nov 27, 2007 Posts: 1811 Location: NJ
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Posted: Fri Jun 27, 2008 10:17 pm Post subject: |
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| Reodor_Felgen wrote: | | I wish they would let Pluto be a planet. Eris should also be classified as a planet, but Ceres shoul be classified as an asteroid. |
Now that seems a bit arbitrary. Granted Ceres is small, but on what grounds is it qualitatively different from Pluto?
Ceres was originally a planet too. Things change. _________________ "My strength is that I can laugh at myself."
"^Your weakness is that you have no choice." |
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TheMidnightJudge autist

Joined: Mar 29, 2007 Posts: 1311 Location: New England
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Posted: Fri Jun 27, 2008 10:47 pm Post subject: |
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The whole Pluto thing makes no sense.
Has the classification "dwarf planet" always existed or did they just make it up for Pluto? If it always existed this change should have been made a long time ago. |
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twoshots Honorary Vertebrate

Joined: Nov 27, 2007 Posts: 1811 Location: NJ
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Posted: Fri Jun 27, 2008 11:37 pm Post subject: |
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| TheMidnightJudge wrote: | The whole Pluto thing makes no sense.
Has the classification "dwarf planet" always existed or did they just make it up for Pluto? If it always existed this change should have been made a long time ago. |
Dwarf Planet was only recently invented (2006). Currently, there are only 3 dwarf planets, officially (Eris, Pluto, and Ceres). In terms of size, Eris>Pluto>Ceres. The official definitions are:
1) A planet1 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) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite. _________________ "My strength is that I can laugh at myself."
"^Your weakness is that you have no choice." |
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sgrannel Phoenix


Joined: Feb 21, 2008 Posts: 505 Location: USA
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Posted: Sat Jun 28, 2008 12:51 am Post subject: |
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I don't care. It's only semantics. We can call it whatever we like, it still is what it is. Not that any of us will ever go there anyway! _________________ You should get to know me better. No one's ever what they seem.-- Shirley Manson |
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youknowandy Blue Jay


Joined: Mar 16, 2008 Age: 31 Posts: 97 Location: Twin Cities, Minnesota
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Posted: Sat Jun 28, 2008 1:19 am Post subject: |
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| wow, i've spent hours discussing planetary definitions and classes on astronomy web sites. i was looking forward to them announcing that we now had twelve planets with many more coming as we learned about the "roundness" of other large solar system bodies. i was disappointed when i learned that they decided Pluto, Ceres, and Eris were not planets. but i was elated that they gave them a new classification of their own to distinguish them from the asteroids and comets and the other eight planets. there IS something different about these bodies and i was glad we now had a term for them. i was relieved that Pluto's orbit would no longer be on the solar system's "map", it was ugly, and i don't want any of these bodies to appear on a "basic" map again. but in the end, dwarf planets are planets no matter what they say. the other "big eight" deserve some kind of special recognition for their domination of their orbits and their ordinal place in the solar system ("dominant planets", "principal planets", or "ordinal planets"), but that doesn't mean that the other objects shouldn't be considered planets. the term dwarf planet works for now, but in the long run is a bad one, since we're likely to discover an object as big as the Earth someday in a highly distant eccentric orbit. |
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V001 Snowy Owl


Joined: Jul 28, 2007 Posts: 141 Location: -0700
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Posted: Sat Jun 28, 2008 10:46 am Post subject: Iam ok with it |
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Iam ok with Pluto getting a new and better term. More info about the inner and outer solor system is being found out and new terms to aid with exploring were needed  |
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Reodor_Felgen Counting down till Castro bites the dust

Joined: Sep 29, 2007 Age: 19 Posts: 1475 Location: Norway
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Posted: Sat Jun 28, 2008 12:12 pm Post subject: |
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| twoshots wrote: | | Reodor_Felgen wrote: | | I wish they would let Pluto be a planet. Eris should also be classified as a planet, but Ceres shoul be classified as an asteroid. |
Now that seems a bit arbitrary. Granted Ceres is small, but on what grounds is it qualitatively different from Pluto?
Ceres was originally a planet too. Things change. |
Ceres was originally known as the largest asteroid, but it's still much smaller than Pluto. _________________ "The urge to save humanity is almost always only a false-face for the urge to rule it."--H. L. Mencken |
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youknowandy Blue Jay


Joined: Mar 16, 2008 Age: 31 Posts: 97 Location: Twin Cities, Minnesota
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Posted: Sat Jun 28, 2008 1:09 pm Post subject: |
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| Reodor_Felgen wrote: | | twoshots wrote: | | Reodor_Felgen wrote: | | I wish they would let Pluto be a planet. Eris should also be classified as a planet, but Ceres shoul be classified as an asteroid. |
Now that seems a bit arbitrary. Granted Ceres is small, but on what grounds is it qualitatively different from Pluto?
Ceres was originally a planet too. Things change. |
Ceres was originally known as the largest asteroid, but it's still much smaller than Pluto. | Ceres was originally known as the largest asteroid, but it's still much smaller than Pluto.[/quote]When Ceres was originally discovered in 1801, it was called a planet and so were the next three "asteroids" discovered. After that, they decided that there were too many planets and to call these smaller things asteroids. |
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curiouslittleboy Deinonychus


Joined: Jun 07, 2007 Age: 20 Posts: 328
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Posted: Sat Jun 28, 2008 1:18 pm Post subject: |
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*Dresses up in black, for mourning purposes*  |
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Tim_Tex WP's Resident Simpsons and South Park Aficionado

Joined: Jul 03, 2004 Age: 28 Posts: 20622 Location: Central Texas
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Posted: Sat Jun 28, 2008 7:14 pm Post subject: |
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So what's the new mnemonic? _________________ When you need something, that's a responsibility, that only an adult...of my maturity...Bunnies!!!
~Meatwad, Aqua Teen Hunger Force |
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burnse22 Phoenix


Joined: Apr 07, 2008 Posts: 514
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Posted: Sat Jun 28, 2008 9:07 pm Post subject: |
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| twoshots wrote: | | (c) has not cleared the neighbourhood around its orbit, |
Because of this I've heard people say that Neptune is now a dwarf planet, as Pluto crosses its orbit twice. _________________ "Was that the bad thing?"
"Floss is boss. Floss is boss! FLOSS IS BOSS!!!" |
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twoshots Honorary Vertebrate

Joined: Nov 27, 2007 Posts: 1811 Location: NJ
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Posted: Sat Jun 28, 2008 9:20 pm Post subject: |
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| burnse22 wrote: | | twoshots wrote: | | (c) has not cleared the neighbourhood around its orbit, |
Because of this I've heard people say that Neptune is now a dwarf planet, as Pluto crosses its orbit twice. |
That would be an odd outcome. However, a more careful reading gives a better interpretation of "cleared the neighborhood"
| wikipedia, who else? wrote: | | ...As a consequence it does not then share its orbital region with other bodies of significant size, except for its own satellites, or other bodies governed by its own gravitational influence. This latter restriction excludes objects whose orbits may cross but which will never collide with each other due to orbital resonance, such as Jupiter and the Trojan asteroids, Earth and 3753 Cruithne or Neptune and the plutinos. |
Another parameter, the "planetary discriminant", which gives the ratio of a body's mass to the sum of the other bodies which share its "orbital zone", not only puts Eris and Pluto nowhere near in the same league as the planets, it actually puts Ceres ahead of the other dwarf planets in terms of its planetness.  _________________ "My strength is that I can laugh at myself."
"^Your weakness is that you have no choice." |
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