Obs. : 2012-12-02 Planet Ly alpha (photons/cm^2/sec) Mercury 4.198e+11 Venus 4.198e+11 Earth 3.791e+11 Mars 4.340e+11 Jupiter 3.888e+11 Saturn 4.031e+11 Uranus 4.075e+11 Neptune 4.174e+11 Pluto 4.278e+11