Re: Jupiter (was PERIHELION etc.)

[Gary Karshner <gkarshner@STMARYTX.EDU>]

        The rate of cooling is complicated by the dense opaque atmosphere
(green house like insolation in the planetary science sense). The
measurement of the excess radiation is based on the equilibrium temperature
of a black body at that distance from the sun verses the measured thermal
radiation  temperature. For example doing this calculation for the Earth
gives an equilibrium temperature of about 300 K. I nice Stefan-Boltzmann
problem.

Gary

At 10:13 AM 1/5/2004 -0800, you wrote:
> "At the bottom is a massive rock & ice core of 10-15 MEarth & ~1.5 REarth."
> [from LK's reference.]
>
>
> Rock includes radioactive nuclei?
>
> Why is the contraction slow -- is the outer shell so non-conductive the
> gravitational pressure is balanced by high temperature?
>
> Core is much more massive than earth's mass tho only ~ 3.4 X volume;
> dense elements? e.g. Th, U, etc.?  K-40 would do it?   It's earth's
> claimed energy source.
>
> Helps:
>
> http://zebu.uoregon.edu/disted/ph121/js19.html
>
> "Thus, this extra heat is leftover energy from the time of Jupiter's
> formation."
>
>
> A simple matter to calculate the rate of energy from core to space and
> determine if "really" from original creation?
>
>
> bc
>
>
>
> Ludwik Kowalski wrote:
>
> >Jupiter radiates into space more "heat" than
> >it receives from the Sun. How can this be
> >explained? According to:
> >
> >http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit6/jupiter.html
> >
> >"Jupiter radiates about 2.5x more energy at
> >Infrared wavelengths than it receives from
> >the Sun. . . .  Jupiter is slowly contracting
> >under its own weight. Slow contraction
> >releases gravitational energy, heating the
> >deep interior."
> >
> >I have no doubt that the radiation difference
> >(emitted versus received) is an experimental
> >fact. But what evidence do we have that the
> >planet is still undergoing slow contraction? Is
> >this only a hypothesis (what else can it be?)
> >or is it a fact based on observations?
> >
> >It seems to me that the rate of contraction
> >would be too small to measure. Yes, the
> >liquid metallic hydrogen (below the thick
> >atmosphere) should be a good conductor
> >of heat and electricity. But this does not
> >explain the origin of conducted heat.
> >
> >By the way, the percentage of hydrogen
> >in Jupiter is nearly the same as in the Sun.
> >But the mass of the planet is about ten
> >times smaller than what would be needed
> >to start thermonuclear burning.
> >Ludwik Kowalski
> >
> >
> >