Obs. : 2010-12-05 Planet Ly alpha (photons/cm^2/sec) Mercury 3.888e+11 Venus 3.788e+11 Earth 3.824e+11 Mars 3.869e+11 Jupiter 3.851e+11 Saturn 3.745e+11 Uranus 3.851e+11 Neptune 3.878e+11 Pluto 3.888e+11