22
Comparison of Jovian Planets
•Variation in distance presumably ultimate causes other effects
–P:      Kepler’s third law
–T:      Falloff mostly just result of falling solar energy
–But Neptune hotter because more internal heat
–M:     Clue to details of solar nebula mode
–Less material in outer solar system – or perhaps less efficient capture
–r:      Should drop with mass because less compression
–Works for Saturn vs. Jupiter
–Increase for Uranus, Neptune indicates less H, He and more heavy material
  2.6
~1
  1.8
  1.7
Eout/Ein
  57
  53
  93
143
    T
  (K)
   1.66
    17
  165
  30.1
Neptune
   1.29
    15
    84
  19.2
Uranus
   0.69
    95
    29
    9.5
Saturn
   1.34
   318
    12
    5.2
Jupiter
   r
(gm/cm3)
   M
(Mearth)
   P
(years)
      a
  (AU)
Planet