So, 12 planets eh?

General physics and astronomy discussions not directly related to Celestia
ANDREA
Posts: 1527
Joined: 01.06.2002
With us: 18 years 4 months
Location: Rome, ITALY

Post #41by ANDREA » 22.08.2006, 22:01

A friend of mine, an Italian astronomer attending the Prague Convention, sent me just now an email informing me that (even if this is not official, obviously), at 06:30 P.M. (GMT time), after a long and very animate discussion, the "double planet" definition has been deleted from the IAU Resolution, so actually Charon's future is back in moons family. :D
Moreover now Pluto is definied as "dwarf planet", head of the new category of "Plutonids". 8O
Well, IMHO from bad to worse. :evil:

Anyhow, this is the new IAU resolution, that almost surely will be approved next Thursday:

*************************************************

Code: Select all

IAU Resolution: Definition of a Planet in the Solar System*

Contemporary observations are changing our understanding od planetary systems, and it is important that our nomenclature for objects reflect our current understanding. This applies, in particular, to the designation 'planets'. The word 'planet' originally described as 'wanderers' that were known only as moving lights in the sky. Recent discoveries lead us to create a new definition, which we can make using currently available scientific information.
*
RESOLUTION 5 (draft c)*
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) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape (NOTE: An IAU process will be established to assign borderline objects into either dwarf-planet and other categories), (b) is the dominant object in its local population zone, and (c) is in orbit around the Sun.

2) A dwarf-planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape (NOTE: An IAU process will be established to assign borderline objects into either dwarf-planet and other categories) and (b) is in orbit around the Sun.

3) All other objects orbiting the Sun, currently including most of the Solar System asteroids, near-Earth objects (NEOs), Mars-, Jupiter-, Neptune- Trojan asteroids, most Centaurs, most Trans-Neptunian Objects (TNOs), and comets, shall be referred to collectively as "Small Solar System Bodies". In the new nomenclature the term "minor planet" is not used.
*
RESOLUTION 6 (draft c)
*The IAU further resolves:

Pluto is a dwarf-planet by the above definition, as are one or more recently discovered large trans-Neptunian objects. Dwarf-planets that have orbital periods in excess of 200years and typically have highly inclined orbits with large eccentricity are designated category of planetary objects, of which Pluto is the prototype, as a new class that we call 'plutonids'.

****************************************************

Well, astronomy is even this, sometimes.
Bye

Andrea :D
Core 2 Quad Q6600 G0 3.8 GHz- 8 GB DDR2
DELL 2709W 1920x1200- WIN 7 64 bit- ASUS P5K-E-
8800 GTX 768MB- 6xSATA II, total 7.5 TB-260.89- Celestia 1.6.1
Celestia1.4.1_patch3- Vincent's LUA Edu Tools 1.2

Malenfant
Posts: 1412
Joined: 24.08.2005
With us: 15 years 2 months

Post #42by Malenfant » 23.08.2006, 00:12

I hate the term "Dwarf Planet", it sounds so stupid!

I have no idea why they suddenly decided to discard the term "minor planet", since that's basically what these bodies are.
My Celestia page: Spica system, planetary magnitudes script, updated demo.cel, Quad system

Hunter Parasite
Posts: 265
Joined: 18.09.2005
With us: 15 years 1 month
Location: CT

Post #43by Hunter Parasite » 23.08.2006, 00:17

This is very depressing.

Topic author
Neethis
Posts: 65
Joined: 10.12.2005
With us: 14 years 10 months

Post #44by Neethis » 23.08.2006, 10:26

:( Im almost sorry I started the topic now... lol
FOR SALE: One small planet, red in colour, two small moons included. Moving due to difficult neighbours. Atmosphere and price negotiable.

Hunter Parasite
Posts: 265
Joined: 18.09.2005
With us: 15 years 1 month
Location: CT

Post #45by Hunter Parasite » 24.08.2006, 00:01

This is just plain sad. I bet they just want to look better than the aliens by saying, "Oh look, we have 12 planets, while you only have 4!!" or something like that.

chris
Site Admin
Posts: 4211
Joined: 28.01.2002
With us: 18 years 8 months
Location: Seattle, Washington, USA

Post #46by chris » 24.08.2006, 00:03

Mostly relevant . . . This is a beautiful diagram of the Kuiper Belt, showing radii, orbits, and resonances (with Neptune) of KBOs:

http://en.wikipedia.org/wiki/Image:TheK ... AU_All.svg

--Chris

Malenfant
Posts: 1412
Joined: 24.08.2005
With us: 15 years 2 months

Post #47by Malenfant » 24.08.2006, 14:17

http://www.space.com/scienceastronomy/0 ... ition.html

The final decision: There are eight official Planets, Pluto isn't one of them. But at least there's none of this "pluton" crap either...
My Celestia page: Spica system, planetary magnitudes script, updated demo.cel, Quad system

Topic author
Neethis
Posts: 65
Joined: 10.12.2005
With us: 14 years 10 months

Post #48by Neethis » 24.08.2006, 14:49

But "dwarf planets".... what was wrong with "minor planets"? :( lol. Apart from that it seems like a fairly good compromise, personally.
FOR SALE: One small planet, red in colour, two small moons included. Moving due to difficult neighbours. Atmosphere and price negotiable.

Scytale
Posts: 51
Joined: 17.02.2005
With us: 15 years 8 months
Location: Romania

Post #49by Scytale » 24.08.2006, 15:02

Hmm... what would Homer say?

Woohoo... in your face, Pluto!
(mumbling)Lousy, icy planetoid with barely enough mass to assume hydrostatic equilibrium...
Einstein would roll over in his grave. Not only does God play dice, but the dice are loaded. (Chairman Sheng-Ji Yang)

Avatar
Joey P. M
Posts: 462
Joined: 28.10.2017
Age: 18
With us: 2 years 11 months
Location: Vladivostok, Russia

Post #50by Joey P. » 18.11.2019, 22:46

We now have the hypothetical planets Planet Ten and Planet Nine (disc. 2016).

Planet Ten is closer to the Sun than Planet Nine, so the sequence goes:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Planet Ten, Planet Nine.

Planet Ten orbits the Sun 60 astronomical units away from the Sun and is estimated to be as massive as Mars. Personally, I want it to be named "Minerva" after the Roman wisdom goddess.

Planet Nine orbits the Sun orbits the Sun up to 500 astronomical units away from the Sun and is estimated to be an ice giant super-Earth at 10 Earth masses. Personally, I want it to be named "Ghost Zone" after the Danny Phantom realm (well, we only knew about it because of its gravitational effect and it's so dark...)

Proof of their existance is the clustering and eccentric orbits of various Kuiper Belt objects and sednoids. They both likely exist; the probability of them not existing and the evidence being nothing more than coincidences is less than 1%!
Joey P.


Return to “Physics and Astronomy”

Who is online