Obs. : 2012-10-04 Planet Ly alpha (photons/cm^2/sec) Mercury 4.232e+11 Venus 4.503e+11 Earth 3.841e+11 Mars 3.851e+11 Jupiter 4.125e+11 Saturn 4.232e+11 Uranus 3.841e+11 Neptune 3.499e+11 Pluto 3.690e+11