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Old 03-01-2016, 03:21 PM   #16
Urwumpe
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Originally Posted by TMac3000 View Post
 Or are there KBOs more massive than Pluto?
Not known, but possible.

A simple mass limit would only be valid for the solar system, not for the whole observable universe. The definition of a Dwarf Planet/Planet is constructed in a way, that it can also be used easily for possible exoplanets and different planet densities.
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Old 03-07-2016, 12:34 PM   #17
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Exclusive photos: Clouds seen on Pluto for first time.
4 March 2016
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Pluto was famously demoted from planethood in 2006, and is now officially a dwarf planet, but these cloud pictures could heighten calls for its reinstatement. The increasingly apparent complexity of Pluto’s atmosphere means it clearly passes what Stern calls the “Star Trek” test – you know a planet when you see one out the window.
https://www.newscientist.com/article...or-first-time/

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Old 03-07-2016, 01:57 PM   #18
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Well - duck-typing for planets. Good luck with it.
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Old 03-07-2016, 04:49 PM   #19
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"It has clouds" is a terrible reason to define something as a planet. Triton has clouds, but it isn't a planet. Titan's surface isn't visible because of how thick the cloud layer is, but nobody is arguing that it's a planet. Saying "Pluto looks like a planet so it is one" is unscientific and kind of insane.
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Old 03-07-2016, 06:22 PM   #20
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 "It has clouds" is a terrible reason to define something as a planet. Triton has clouds, but it isn't a planet. Titan's surface isn't visible because of how thick the cloud layer is, but nobody is arguing that it's a planet. Saying "Pluto looks like a planet so it is one" is unscientific and kind of insane.
Also it depends on the perspective. If you are close enough to it, it looks like a planet. If you are far enough away from it, it is just a huge rock among many, but is no distinct, significant planet of the star.

As Star Trek navigator, I would never call Pluto a planet, but then, in TNG, even a Pluto with a much denser atmosphere would be considered to be an asteroid.
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Old 03-07-2016, 06:37 PM   #21
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Depth perception in a vacuum is more difficult too. A cleverly painted basketball could look like a planet from your spacecraft's windows. If we gave such a basketball a name-tag that said "Pluto", would people argue for its status as a planet?
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Old 03-07-2016, 06:45 PM   #22
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Its the only body named after a cartoon dog. For that alone, it should get reinstated. Have these astronomers no sense of humour?

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Old 03-08-2016, 03:19 AM   #23
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Originally Posted by Lmoy View Post
 "It has clouds" is a terrible reason to define something as a planet. Triton has clouds, but it isn't a planet. Titan's surface isn't visible because of how thick the cloud layer is, but nobody is arguing that it's a planet. Saying "Pluto looks like a planet so it is one" is unscientific and kind of insane.
Alan Stern is the leading expert on Pluto and the principle investigator (PI) for the New Horizons mission. There are several reasons why he suggests Pluto should be classified as a planet. I suspect he's being humorous here.

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Old 03-08-2016, 07:31 AM   #24
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Its the only body named after a cartoon dog.
It is? I always thought it was named after the god of the underworld...
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Old 03-08-2016, 08:51 AM   #25
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No, Disney hired famous animator Clyde Tombaugh, and he created Pluto in 1932. I've seen the movies.

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Old 03-08-2016, 08:56 AM   #26
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 Its the only body named after a cartoon dog. For that alone, it should get reinstated. Have these astronomers no sense of humour?

N.
Eris is short for Ed Harris. Who played Gene Krantz in Apollo 13. or what did you think the name was chosen for?
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Old 03-08-2016, 10:05 AM   #27
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As much as I admire Ed Harris, fine actor that he is., who could forget him in Coma as patient number 2. I have.
However he doesn't come close to Pluto at his best...:https://www.youtube.com/watch?v=gl8fMiDCHYQ

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Old 03-08-2016, 11:33 AM   #28
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As Star Trek navigator, I would never call Pluto a planet, but then, in TNG, even a Pluto with a much denser atmosphere would be considered to be an asteroid.
Dr. Alan Stern, as chief science officer on the starship would call it a planet.

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Old 03-08-2016, 11:59 AM   #29
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 Dr. Alan Stern, as chief science officer on the starship would call it a planet.

Bob Clark
The captain would sure like to beam him on the surface...
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Old 03-08-2016, 01:19 PM   #30
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 "It has clouds" is a terrible reason to define something as a planet..
I agree. By itself, that's a pretty bad reason.

But "It has clouds" combined with "It orbits the Sun" is quite convincing. That wouldn't demote any of the classical planets, and also would not promote anything in the Asteroid belt or Kuiper Belt (unless Ceres or Sedna could be shown to have atmospheres).

Of course, you can't require both, or Mercury would not be a planet. But both together should give an object the status of planet.

In other words: if it orbits the sun, it might be a planet (Ceres isn't). If it has an atmosphere, it might be a planet (Titan isn't). If it meets both, it is certainly a planet. (If Titan broke orbit with Saturn and started orbiting the sun, it would become a planet).

Last edited by TMac3000; 03-08-2016 at 01:23 PM.
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