New Horizons flyby of Pluto

[maksimsmelchak]

Fair point, but when is a Union not a Union?

It's really not that kind of union. It's really just a professional association for setting international standards in Astronomy and promoting Astronomy education. It's not in any way a labour union.

Simon Hibbs

I see what you are saying Simon and agree with you.

I think, more to the point, is that the IAU sometimes acts like a bad committee exhibiting the worst aspects of human bureaucracy...

These kinds of talks remind of Congress or Parliament at their worst... I wish there were a lot less politics in science... And in Hollywood, science fiction, television, and basically everywhere else.

Pluto, as a planet, does not seem problematical on many levels.

But, hey, at least they are not Bwaps! that's some REAL bureaucracy! LOL ;-)

With positive regards for all!

Shalom,
Maksim-Smelchak.

 

[whulorigan]

If you could see it in the night sky, it was a star. :ssb:

Unless, of course, it was a "wandering star" (Gr. "Aster Planētēs") that messed up your navigation when you accidentally took your bearings from it instead of the fixed star that you had intended. Then it was a "planet".

 

[aramis]

I see what you are saying Simon and agree with you.

I think, more to the point, is that the IAU sometimes acts like a bad committee exhibiting the worst aspects of human bureaucracy...

These kinds of talks remind of Congress or Parliament at their worst... I wish there were a lot less politics in science... And in Hollywood, science fiction, television, and basically everywhere else.

Pluto, as a planet, does not seem problematical on many levels.

But, hey, at least they are not Bwaps! that's some REAL bureaucracy! LOL ;-)

With positive regards for all!

Shalom,
Maksim-Smelchak.

http://blogs.discovermagazine.com/crux/2015/02/25/pluto-ceres-planet-again/#.Vaev2xNViLE

Pointing it out mostly for it reporting the deceptive tactics used to put the redefinition through.

To be blunt: it had been tabled until next meeting. Neil Tyson used tricks of parliamentary procedure to get it untabled once his opponents had left.

And a significant (perhaps not enough) number of members of the IAU want the Tyson definition scrapped as unworkable. The New Horizons mission may just give enough ammo (and public pressure) to undo Dr. Tyson's efforts.

 

[simonh]

Pointing it out mostly for it reporting the deceptive tactics used to put the redefinition through.

To be blunt: it had been tabled until next meeting. Neil Tyson used tricks of parliamentary procedure to get it untabled once his opponents had left.QUOTE]

That's not good. But then what's the alternative definition? 'It was a planet when I was growing up' doesn't seem very satisfactory, but actualy It's the only one I've seen anyone propose in any of the various places I've discussed this.

I'm surprised the article doesn't mention Eris, which is actually more massive than Pluto and is also much bigger than Ceres as are Haumea, Makemake, Orcus, Salacia, Quaoar, Sedna and several other objects with less interesting names. Actualy Ceres should be very far down the list of candidates for planethood. I can only assume the author mentioned it so much because it's so well known, not because it has any particular claim.

Simon Hibbs

 

[aramis]

The primary alternative definition:

Planet, major: self-rounding body in solar orbit and at least (IIRC) 1000km radius.
Planet, minor: any body in solar orbit that isn't that big.
Moon: any body orbiting a larger body.

I remember that Size S Traveller worlds (MGT size 0 - note that MGT deviated from the rest) weren't big enough to qualify.

 

[Magnus von Thornwood]

Aw, boo-hoo, poor Pluto.

:rant: I must be one of the few people in the world who is perfectly okay with Pluto being demoted from full planet to dwarf planet. In fact, I find the term "dwarf planet" annoying as hell. What the fanark is wrong with demoting to its proper place, Kuiper Belt Object? I mean that is what it is, rounded, cleared orbit or not, it is present and one of just many bodies resident in the Kuiper Belt so to me it is just the most well known of the Nav Hazards of the Outer System.

Seriously, you dirtsiders and your sentimentality astounds me.

 

[simonh]

The primary alternative definition:

Planet, major: self-rounding body in solar orbit and at least (IIRC) 1000km radius.
Planet, minor: any body in solar orbit that isn't that big.
Moon: any body orbiting a larger body.

I remember that Size S Traveller worlds (MGT size 0 - note that MGT deviated from the rest) weren't big enough to qualify.

I think an arbitrary size limit may be the way we'll have to go when considering exoplanets, because we're likely to encounter situations where a system is still forming and not all potential planets have 'cleared their orbits'.

In Traveller terms, a planet would be any object in stellar orbit of Size 1 or more.

Simon Hibbs

 

[aramis]

I think an arbitrary size limit may be the way we'll have to go when considering exoplanets, because we're likely to encounter situations where a system is still forming and not all potential planets have 'cleared their orbits'.

In Traveller terms, a planet would be any object in stellar orbit of Size 1 or more.

Simon Hibbs

Only going to be relevant if the eagleworks measurements are in fact measuring what Dr. White thinks they're measuring.

Then again, the Chinese have had similar results.

 

[Frankymole]

The trojan asteroids are gravitationally bound to Jupiter. At Jupiter's trojan points. Hence the name

They share an orbit around the sun with Jupiter, sure. In that case you could argue all the asteroid belt asteroids are bound the Ceres and that Ceres is as much a planet as Jupiter.

Or, as we all share a common centre of gravity, we're all "gravitationally bound" to each other (especially to Jupiter) and so everything that orbits the sun is a planet.

 

[aramis]

They share an orbit around the sun with Jupiter, sure. In that case you could argue all the asteroid belt asteroids are bound the Ceres and that Ceres is as much a planet as Jupiter.

Or, as we all share a common centre of gravity, we're all "gravitationally bound" to each other (especially to Jupiter) and so everything that orbits the sun is a planet.

Actually, they orbit jupiter with a period that has the same total length as its orbit around the sun.

Which is how you locate the lagrange/trojan points. Earth's trojan points (Sun is A, earth B) are almost empty. (ISTR 1 earth trojan... 2010 TK₇)

https://en.wikipedia.org/wiki/Earth_trojan
https://en.wikipedia.org/wiki/2010_TK7
http://news.nationalgeographic.com/...teroid-earth-planet-orbit-nasa-space-science/

Mathematically, a trojan asteroid is NOT dominated by the planet it's linked to; it's balanced between the star and the planet's effects, and technically orbits both of them.

Most of the IAU treat it as being dominated by the planet, but that's not the math.

 

[Frankymole]

Interesting, I wonder what the dark stuff is?

http://www.theguardian.com/science/...esolution-image-delights-intrigues-scientists