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Tweef
2006-Jul-14, 09:47 AM
What is the official status of Pluto and Xena now? Planets or not?

Infinity Watcher
2006-Jul-14, 10:02 AM
AFAIK Pluto is currently still a planet but due to the debates on what is a planet this may not last depending on what the final decision is.

Xena I don't know about.

Bellatrix
2006-Jul-14, 12:23 PM
IIRC the IAU will issue the "definition of a planet" early September 2006. Should be interesting.

Saluki
2006-Jul-14, 02:02 PM
Until September, there is no official definition of a planet, so I guess technically all of them are on the bubble. However, if the IAU were to formulate a definition that included less than 8 in the Solar System, I would wonder what exactly was in the water in the Czech Republic.

ciderman
2006-Jul-14, 10:26 PM
I believe a lot of absinthe is produced there, so the results could be suprising indeed!

Dragon Star
2006-Jul-14, 10:30 PM
Until September, there is no official definition of a planet, so I guess technically all of them are on the bubble. However, if the IAU were to formulate a definition that included less than 8 in the Solar System, I would wonder what exactly was in the water in the Czech Republic.

"Less than 8" or 8 or less?

ToSeek
2006-Jul-14, 10:33 PM
Fewer than 8

Dragon Star
2006-Jul-14, 10:37 PM
Ok, I just seemed to remember, actually I think it was you that said it ToSeek, that it would be 8 or 10 either way some time ago, but I don't know, perhaps I am out of my mind.

ToSeek
2006-Jul-14, 10:43 PM
I don't see how they could come up with fewer than 8, unless they're planning to demote Mercury. I think the possibilities are:

8 - Planets have to be unique in their domain
10 (and counting) - Anything bigger than Pluto
12 (or so) - Anything round and not orbiting a planet is a planet

Bellatrix
2006-Jul-17, 12:44 PM
How about anything that's further away than Pluto (distance from sun) has to be bigger than Pluto and has to have it's own satellite?

jseefcoot
2006-Jul-17, 08:49 PM
I don't see how they could come up with fewer than 8, unless they're planning to demote Mercury. I think the possibilities are:

8 - Planets have to be unique in their domain
10 (and counting) - Anything bigger than Pluto
12 (or so) - Anything round and not orbiting a planet is a planet


12 or so? Only for like the first two weeks after they make their decision. You know every nut with a great telescope is gonna be out there every night trying to find a new planet. . . . . . .We'll never keep up with all the names:sad:

But if that gets more people interested in astronomy, I really shoudn't complain. I hate being the only person I know who is aware of a shuttle launch.

Tim Thompson
2006-Jul-17, 09:13 PM
"Xena" is offically still known as 2003 UB313 (http://www.gps.caltech.edu/~mbrown/planetlila/index.html). The IAU says it will publish the official definition of a planet at the beginning of September (IAU note (http://www.iau.org/TRANS-NEPTUNIAN_OBJECT_2003_UB.324.0.html?&0=)). The official IAU status of Pluto (http://www.iau.org/STATUS_OF_PLUTO.238.0.html) at the moment is that it is the ninth planet. The IAU did not decide that Sedna (http://www.gps.caltech.edu/~mbrown/sedna/) was a planet because it is smaller than Pluto, and on an extremely eccentric 10,000 year orbit, much unlike any planet orbit (IAU: Naming of Planets and Sedna (http://www.iau.org/NAMING_PLANETS_AND_SEDNA.239.0.html)). Since 2003 UB313 is on a planetary like orbit, and is larger than Pluto, I don't see how the IAU can avoid designating that object as the official 10th planet. I am also quite convinced that Pluto will not be "demoted" from planetary status, simply because doing so would be far too controversial. Come Spetember, there will be 10 planets. 2003 UB313 will also definitely not be named "Xena", which is Brown's own name for his discovery.

aurora
2006-Jul-17, 11:13 PM
I don't see how they could come up with fewer than 8, unless they're planning to demote Mercury. I think the possibilities are:

8 - Planets have to be unique in their domain
10 (and counting) - Anything bigger than Pluto
12 (or so) - Anything round and not orbiting a planet is a planet

One other possibility might be if they just sidestep the whole issue by saying that there are 3 or 4 types of planets and giving each type a name. So there would be rocky, gas giant, ice giant (if Uranus and Neptune are different enough from Jupiter and Saturn), and whatever kuiper belt objects would be called. To sidestep the issue they could say that "planet" is not a scientific term, and is to be replaced with the different types of objects just mentioned.

ZaphodBeeblebrox
2006-Jul-17, 11:32 PM
One other possibility might be if they just sidestep the whole issue by saying that there are 3 or 4 types of planets and giving each type a name. So there would be rocky, gas giant, ice giant (if Uranus and Neptune are different enough from Jupiter and Saturn), and whatever kuiper belt objects would be called. To sidestep the issue they could say that "planet" is not a scientific term, and is to be replaced with the different types of objects just mentioned.
Maybe:

Rock Dwarf

Gas Giant

Ice Giant

Ice Dwarf
There, Problem Solved!

jseefcoot
2006-Jul-18, 06:03 PM
Maybe:

Rock Dwarf

Gas Giant

Ice Giant

Ice Dwarf
There, Problem Solved!

Sounds like a role-playing game! Works for me. Easy to remember too.

jlhredshift
2006-Jul-18, 06:10 PM
Then Ceres would be a rock dwarf?

ZaphodBeeblebrox
2006-Jul-19, 04:46 AM
Then Ceres would be a rock dwarf?
Something Liike That ...

Probably ANYTHING ...

Massive Enough to Make itself Spherical!

:think:

SilverAssassin
2006-Jul-21, 04:41 PM
In my opinion, Pluto will go, along with the rest of the KBOs, and unless something wacky (well, wacky in astronomical terms!) happens, like we find another gas giant orbiting at 90 degrees to the other planets' plane, we'll stick with 8 for the foreseeable future.

Bellatrix
2006-Jul-23, 07:30 PM
In my opinion, Pluto will go, along with the rest of the KBOs, and unless something wacky (well, wacky in astronomical terms!) happens, like we find another gas giant orbiting at 90 degrees to the other planets' plane, we'll stick with 8 for the foreseeable future.

Pluto can't go (in my opinion) for historical reasons. We've made our bed.....let's lay in it. We have to classify according to what we've got. Definition of "PLANET" early September. ...by IAU.

jkmccrann
2006-Jul-23, 08:01 PM
Pluto can't go (in my opinion) for historical reasons. We've made our bed.....let's lay in it. We have to classify according to what we've got. Definition of "PLANET" early September. ...by IAU.

Are you aware that Ceres was called a Planet by the astronomical community for most of the 19th century?

Didn't stop its demotion when it was found to merely be one body among many in that region of Space.

A precedent for demoting Pluto is right there really.

Inferno
2006-Jul-25, 12:07 AM
Practical solution - When they come up with the definition of a planet neither Xena nor Pluto will classify, but for historical reasons they'll let Pluto keep its planet status.

Ilya
2006-Jul-25, 12:24 AM
Practical solution - When they come up with the definition of a planet neither Xena nor Pluto will classify, but for historical reasons they'll let Pluto keep its planet status.
Is this your suggestion, or are you claiming that's what IAU will do?

Inferno
2006-Jul-25, 07:06 AM
Is this your suggestion, or are you claiming that's what IAU will do?

Both. Not that I have any intimate working knowledge into the IAU, but seems like a good answer.

Skyywatcher
2006-Jul-25, 10:50 PM
Agree with Inferno.

ToSeek
2006-Jul-28, 09:59 PM
Practical solution - When they come up with the definition of a planet neither Xena nor Pluto will classify, but for historical reasons they'll let Pluto keep its planet status.

If I were a betting man, that's the outcome I'd put my money on.

94z07
2006-Jul-29, 02:08 PM
Iíve not found any consistent definition for asteroids and meteoroids that would allow one to differentiate between the two. In general, Iíve found that people are more likely to label something an asteroid if itís large (subjective) or if it is in an asteroid belt. One source said that objects over one mile across are asteroids and smaller objects are meteoroids.

If a meteoroid strikes Moon is it then a meteorite or since it hasnít struck Earth is it a meteoroid resting on or near the surface of Moon?

If an asteroid came to Earth what would one call the visible path in the atmosphere? Would it be called a meteor? Would it be called an aster? (Aster in Latin means star.)

When an asteroid hits Earth is it called a meteorite? Would it be better to call it an asterite?

dtilque
2006-Jul-30, 08:43 AM
When an asteroid hits Earth is it called a meteorite? Would it be better to call it an asterite?
I'd call that a dis-aster...

94z07
2006-Jul-30, 03:21 PM
I'd call that a dis-aster...
ahahahahahahahah! :clap: :clap: :clap: :clap: :clap: :clap:

Peter Wilson
2006-Aug-01, 10:40 PM
Something Liike That ...

Probably ANYTHING ...

Massive Enough to Make itself Spherical!

:think:Cows are approximately as spherical...

Chuck
2006-Aug-03, 12:09 AM
Gas giants and rocky planets are not all that similar so the gas giants should be reclassified as small stars. That would put us in a quintuple star system. The gas giants' moons are promoted to planets because they orbit stars so the solar system would have a very large number of planets. Their rings become asteroid belts. Pluto and Charon are Kuiper Belt objects because they're so far out. Phobos and Deimos are capured asteroids because they're so small. This means that the earth would be the largest planet and the only one with a moon. That should make religious folks happy. It doesn't put us back in the center of the universe but it does make us doubly special.

Gillianren
2006-Aug-03, 04:08 AM
Gas giants aren't stars. No fusion.

Kaptain K
2006-Aug-03, 02:06 PM
Gas giants are not stars. They do not now, have not ever, and will not ever generate heat by fusion (the definition of a star)!

Peter Wilson
2006-Aug-04, 07:57 PM
Until September, there is no official definition of a planet, so I guess technically all of them are on the bubble. However, if the IAU were to formulate a definition that included less than 8 in the Solar System, I would wonder what exactly was in the water in the Czech Republic.

I couldn't tell you what's in the water, but "planet" originally meant those points of light in the sky that wondered, or moved, with respect to the other lights in the heavens. Thus, for the sake of tradition, I would say reserve the word "planet" for Mercury, Venus, Earth, Mars, Jupiter & Saturn. Period.

Everything else more spherical than a cow, and not in orbit around another planet, would be a "planet with qualifier." E.g. Uranus, Neptune, Pluto & Xena would be "telescopic planets."

Planetary bodies around other stars would be "exo-planets."

Bob
2006-Aug-04, 08:29 PM
Uranus can be seen with the naked eye, so it's not a "telescopic planet." Vesta can also be seen with the naked eye. Is it a planet?

Spaceman Spiff
2006-Aug-04, 09:06 PM
Gas giants are not stars. They do not now, have not ever, and will not ever generate heat by fusion (the definition of a star)!

Be careful!
Is a brown dwarf a star? They do undergo deuterium (M > 13 M_Jupiter) and lithium (M > 60 M_Jupiter) fusion for a period of time before exhausting these "fuels". The most massive BDs sputter about in the p-p chain, but cannot establish energy equilibrium with losses at the surface in the form of light.

What's the line between gas giants and BDs? It's not so simple because the above mass limits for D and Li fusion aren't hard and fast (depend on things like elemental abundances).

Nevertheless, I do agree with the gist of your post in that the Jovians shouldn't be called "stars".

Kaptain K
2006-Aug-05, 04:09 PM
OK, I over-simplified a bit, but since the minimum mass of a brown dwarf is on the close order of 13 times the mass of Jupiter, my point was that the Solar System gas giants do not, in any way, fit any definition of a "star".