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Old 14-April-2005, 03:49 AM
Yisrael Asper Yisrael Asper is offline
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Sign on to the below Petition to the IAU, the International Astronomical Union or help make a consensus to modify this one. There will be a conference in Prague by the IAU in 2006. Email me at yisraelasper@hotmail.com to find yourself included or removed below through my editing this message.

To whom this may concern
Below are the proposed definitions of a planet and a moon of an object based
both on what the IAU has been saying in addition to the public's usage. Pluto would still be counted as a planet for historical reasons and the public would still feel that it is not completely arbitrary in still having Pluto recognized as a planet since it was considered so under the assumption that it was the Planet X which was good scientific theory for it's day.

The definition of a moon below at present is not accepted as any, even strangely shaped world is considered a moon as long as it orbits a planet but it has led to too much of a discrepancy between what people think of as a moon and what is scientifically at present defined as a moon. Over time definitions for astronomical objects have changed and it is really a matter of language with people also being used to surprising scientific differences from what they would call the definition otherwise but it is time to try to make the definition of a moon of an object to be more in accordance with what people picture at this time.

Thank you
Yisrael Asper
yisraelasper@comcast.net
yisraelasper@hotmail.com
yisraelasper@yahoo.com
yisraelasper@msn.com

Definition for a planet and a moon
__________________________________________________ _____________
Definition of a Planet
Pluto and objects with true masses below the limiting mass for
thermonuclear fusion of deuterium that orbit stars or stellar remnants are
"planets" provided they have orbital inclinations at least roughly enough on
their planetary planes so that they do not have orbits that cross the orbits of other planets or belts of material with orbital inclinations that follow the same standard as planets. The minimum mass/size required for an object to be considered a planet should be the amount needed to have gravity round the object towards its common center.

Definition of a moon of an object
Any object orbiting planets bordering the Asteroid Belt of our Solar System
and outward until the border of the outer Solar System of ours' belt and any
object that would be considered a planet if what it orbits is treated as a
star or stellar remnant is a moon of an object with the exception that
whatever characteristic of a planet is lacking in the object treated as a
star or stellar remnant can lack in the moon.
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Old 14-April-2005, 03:39 PM
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antoniseb antoniseb is offline
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I don't like these definitions, as they aren't really any more precise than the vague usage commonly in place today, for example:
Quote:
provided they have orbital inclinations at least roughly enough on
their planetary planes...
Personally, I think that if we are going to look for precision, we do NOT need to impose it on these quaint old terms. We can describe Jupiter (Sol-e) as a 2x10^30 gram object orbiting a type G subdwarf (Sol). We can describe Europa as Sol-e-3, a 5x10^25 gram object orbiting Sol-e. If a one kilometer block of ice is found orbiting Europa, it could be Sol-e-3-a, a 10^15 gram object orbiting Sol-e-3.

Naturally, the descriptions can also include statements about the orbital inclination and eccentricity (etc) with respect to the largest orbiting object.

Note well, that my [Sol-e-3-a] system is a hack job, and my first attempt at something like this. If we collectively gave it some thought we could come up with a system that would work for all of the asteroids, comets, KBOs, large chunks in planetary ring systems, and old dead rocket boosters floating around up there.

There is no need to use the terms Planet or Moon when you are looking for precision.
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Old 14-April-2005, 03:52 PM
Yisrael Asper Yisrael Asper is offline
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I have based my definition which is vague still but tries to avoid having arbitrariness on what is likely to pass and has already been. There is not one moon or planet that would be excluded by my definition. In any event what is your definition of a Planet and a Moon of an object? I'm trying to reach a consensus.
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