Re: Planet Definition revised

steve wrote:
To bring some commonsense to this argument and keep the number of
planets down to a managable number, I propose :-

1)Minimum size should be radius of 2 440km or mass of 3.302 × 1023 kg
(bigger than Mercury) This is an arbitary number but is required for
our definition. I favour working by mass.

I favor working by natural criteria rather than arbitrary criteria.

Roundness is not arbitrary, it takes a certain amount of mass and composition to do it properly.

2)Does not and has not produced substantial energy naturally by any
nuclear fusion mechanism (not a star)

3) Is in orbit around a star

4) Local system is defined as Planet and moon if COG outside of
planet. Planet and planet if COG outside of both planets if all above
rules are obeyed.


If we want to keep Pluto change the minimum diameter to 1 151km or mass
of 1.25 × 1022 kg

Pluto is roughly round, so arbitrary mass criteria are unnecessary.

Pluto is easily a planet.

http://cosmic.lifeform.org
.

Relevant Pages

  • Re: Our expanding earth - video
    ... So why are planets round? ... sufficient mass, and sufficient pressure of these waves, pushing out, ... The question I have always had though is if, a planet, could form, by ... well be Bose Einstein condensate. ...
    (sci.physics)
  • Re: mass increase due to speed
    ... and if "inertial mass" changes then so does ... All mass measurements in your frame are with respect to other ... To rephrase the question, if a planet flies by us going "real fast", ... acceleration depends on its velocity. ...
    (sci.physics.relativity)
  • Re: Conservation of momentum (and a weird space drive)
    ... >>planet with mass M having a tall tower. ... > and opposite to the force on the planet. ... and is turned into heat. ... You have a solar sail, and you shine a light on it, if all ...
    (sci.physics.relativity)
  • Re: Question about Typesafe Enums
    ... > planets and each planet has two specific values, a mass and a radius. ... would it be possible to set up other enums to ... let's say we have an array called Planet and it looks like this (I'll ...
    (comp.lang.java.programmer)
  • Astronomers Find First Habitable Earth-like Planet (Forwarded)
    ... ESO Education and Public Relations Dept. ... Astronomers have discovered the most Earth-like planet outside our Solar ... for the presence of a third planet with a mass about 8 Earth masses. ... This exoplanet -- as astronomers call planets around a star other than the ...
    (sci.astro)