Recent content by rieman zeta

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    Planetary retention of atmospheres

    Sir: "Basically, you just need to calculate the thermal timescale (relaxation time of the particles) and fraction of the MB distribution with speeds greater than the escape speed. Since heavier particles will thermalize to lower average speeds, it will be easier for atmospheres to retain...
  2. R

    Triton Nucleus & C14: Radiogenic Properties & Instability

    Thank you for your reply. I was hoping for a connection to some underlying principle. For example, if you add the right number of neutrons then stability ensues. The wrong number and you get instability. What is the right and wrong #s criterion. Perhaps it could be approached through the...
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    Planetary retention of atmospheres

    To all: By memory I have seen in the literature the factor 1/6 when analytically discussing the retention of a planetary atmosphere (more correctly a particular specie of molecule in the atmosphere). The relation would go something like this: Atmospheric mean thermal speed of molecule <...
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    Triton Nucleus & C14: Radiogenic Properties & Instability

    To all: In some detail what makes the tritium isotope of hydrogen radiogenic? And since C12 and C13 are both stable what makes C14 unstable? Thanks Rieman Zeta
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    Compute Tidal Locking Radius: Planet/Moon Area

    thanks Although I am light years ahead of where I was before your reply, I would invite others to continue to edify me. Thanks Riemann Zeta
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    Compute Tidal Locking Radius: Planet/Moon Area

    How does one compute the tidal locking radius of say a planet on a putative moon its area? Is there a formula? rieman zeta
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    Maximizing Velocity Excess: The Power of Perihelion Gravity Assists

    powered gravity assist sir: A spacecraft with rocket capability approaches the sun from infinity in a parabollic orbit. It has a twin folowing. The first fires its rockets tangent to its trajectory and opposite the direction of motion at 3 times the radius of the Sun. Later, the second waits...
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    Maximizing Velocity Excess: The Power of Perihelion Gravity Assists

    could you be a little less opaque please. jbf
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    Maximizing Velocity Excess: The Power of Perihelion Gravity Assists

    why does firing your rocket engines (obviously in the appropriate direction) at perihelion give the greatest velocity excess at infinity?
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