Obs. : 2011-02-06 Planet Ly alpha (photons/cm^2/sec) Mercury 3.692e+11 Venus 3.649e+11 Earth 3.801e+11 Mars 3.692e+11 Jupiter 3.809e+11 Saturn 3.822e+11 Uranus 3.811e+11 Neptune 3.744e+11 Pluto 3.634e+11