Why Do 8 Other Planets Exist?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by BlackRazor, Nov 24, 2006.

  1. leopold Valued Senior Member

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    only because of its thin atmosphere.
    if enough greenhouse gases were introduced you would have a lush, viable, biosphere. all you would need to do then is add humans and let the trashing begin.
     
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  3. invert_nexus Ze do caixao Valued Senior Member

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    The problem with Mars is that the gravity is too weak and any atmosphere introduced would slowly leak out into space again.


    Speaking of atmospheres, someone earlier mentioned that Pluto doesn't have an atmosphere. Well, technically, Pluto isn't a planet anymore, but I suppose it'll likely fall into planetary discussions for some time to come.

    Anyway. It does have an atmosphere. And what is interesting about is that when it is closest to the sun, the atmosphere melts and envelopes the planet, but when it moves further away, it freezes and settles down on the surface of the... kuiper belt object in a frost.

    There is a probe being sent out to Pluto right now. Hopefully it'll get there in time to study it while the atmosphere is hot.
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Thanks. I do not have time to go to your references just now, but already know that even the solar system is chaotic on long time scale - part of the reason I asked james R why he thinks a big planet makes a smaller one stable. I once had a good course in stastical mechnics, know about the ergotic* theorm, etc all closely related to chaos theory.
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    *May not be spelled corectly but basically states that any n-particle system, when described as a point in "6n phase space" will eventually come arbitarly near any point in that 6n space which has the system energy, etc. The ergotic theorm seems to me to imply James is wrong as if earth is small relative to the big planet, then the energy needed to expell earth from the sun could easily be "borrowed" from the big planet and energy conserved. - I.e. a point in 6n phase space (where n=3 in this Earth, sun and big planet case or total of nine position and nine velocity componets in 18 basis vector phase space) with Earth's (x,y,z) lightyears from the sun will some day be the Earth's location if the Ergotic therom is true (and it is).
     
    Last edited by a moderator: Nov 27, 2006
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  7. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    This is mainly a thin atmosphere effect as someone else noted, but the eccentricity of Mars is one of the largest* so the Martian year will have considerable variation also. Even if an atmospheric blanket of some heavy gas that Mar's gravity could retain were added, living there on surface might be thermally tough.

    In my book, Dark Visitor, an object with the 2.2 solar masses, but not capable of reflecting sunlight (probably a typical** small black hole) will soon pass by the solar system and increase Earth's eccentricity slightly (still remaining less than Mar's). Because Earth is already on the edge of an ice age, this small change throws Earth into a permanent ice age. (But only in the Northern Hemisphere where slightly closer to sun winters are milder with lots of snow and the colder following summers do not melt all that fell in the prior winter with accelerating albedo effects.) Washington DC is under 100 feet of ice in less than 100 years; all of world's ports are useless in 10 years as sea levels drop, etc. - Mankind's worst ever disaster, but life in Brazil, where I live, is still possible. More details at web site under my name, including how to read book for free.
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    *May be the largest of all planets now that Pluto is not a planet. - I forget and too lazy to check.
    **There are probably more of these small black holes than all the stars that have ever existed, but they cannot be detected, prior to gravitational disturbance of solar bound objects for reasons I have discussed in other threads. Perhaps they are the 90+% of "dark matter" filling the universe?
    Most, like stars, come in gravitationally bound pairs. The first of this pair passed by solar system in late 1920s, and caused the perturbation of Neptune that lead to the search which found Pluto, but it is now known that Pluto, which is smaller than the moon, could not have been the cause of the observed perturbation of Neptune.
     
    Last edited by a moderator: Nov 27, 2006
  8. Galactic_Command Registered Member

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    7
    Creation of the Universe itself appears to be a random chance event.

    Why do billions of stars exist.?? Nature operates on an impersonal level. If life arose it also is an random chance event.

    Life itself is resilient. It can exist anywhere.
     
  9. eburacum45 Valued Senior Member

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    1,297
    I can only re-iterate; the other planets are necessary, because if they did not exist in the forms which they have, then the Earth would be different. If for instance Venus had not formed, then the portion of the primordial cloud which accreted together to form that planet would have gone somewhere else. A portion of that mass may well have have impacted the Earth, thereby changing the characteristics of our planet in one way or another.

    Certainly the formation of planets is a random, i.e. a stochastic process, and there is no purpose behind the formation of the solar system as it is; but if the planets in our system had formed differently, then the Earth as we know it would be different as well to some greater or lesser degree.
     
  10. orcot Valued Senior Member

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    Do you think that life on earth would have been different if for example mars had 2 times it mass, or venus half it's mass?
     
  11. eburacum45 Valued Senior Member

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    If such a small change were the only difference in the entire solar system, there would be some relatively minor but noticable changes to our Earth; we would occupy a slightly different orbit, and the patterns of precession and Milankovich cycles would be slightly different. This could lead to quite drastic changes in our current climate- we might currently be in a glaciation period, for instance, if it were not for the subtle influence of Mars or Venus.

    Even a distant planet such as Neptune is very important in maintaining the patterns of deep space objects in the outer solar system.

    But the biggest influences on the characteristics of our world (I should think) come from Jupiter, and from our own Moon. The exact size and orbit of the Moon can be regarded as consequences of the precise angle and velocity of the impact which is thought to have produced our satellite more than four billion years ago; a slightly different angle, or a slightly more energetic impact, could have produced two or more moons, or a smaller or larger single example, or a more distant Moon with less powerful tidal effects. And that impact event, long ago, was the result of many random factors.
    A little alteration to the mass distribution in the primordial cloud would result in a markedly different planet in place of Earth.
     
  12. Itseemstome Registered Senior Member

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    103
    I read somewhere that the planets we have found orbiting other 'suns' would appear to be in the same ratio of distances from their sun as our planets are from ours. Interesting. Or at least I think so!
     
  13. Roman Banned Banned

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    It's this sort of middling bullshit that should exclude you from ever being a mod at these forums.
     
  14. Roman Banned Banned

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    I thought it was because the core had gone solid and stopped spinning. With out the magnetic fields, solar winds strip the atmosphere of gases.

    Does that have anything to do with exploring 3d space?
    I heard that if one randomly explores a three dimenionally space, moving randomly from one point to an adjacent point, there's a chance that one will never explore the total volume.
     

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