Obs. : 2010-02-10 Planet Ly alpha (photons/cm^2/sec) Mercury 3.557e+11 Venus 3.634e+11 Earth 3.862e+11 Mars 3.817e+11 Jupiter 3.634e+11 Saturn 3.760e+11 Uranus 3.640e+11 Neptune 3.634e+11 Pluto 3.485e+11