Obs. : 2013-05-06 Planet Ly alpha (photons/cm^2/sec) Mercury 4.148e+11 Venus 4.119e+11 Earth 4.510e+11 Mars 4.148e+11 Jupiter 4.099e+11 Saturn 4.485e+11 Uranus 4.287e+11 Neptune 4.380e+11 Pluto 4.478e+11