Obs. : 2013-03-13 Planet Ly alpha (photons/cm^2/sec) Mercury 4.412e+11 Venus 4.346e+11 Earth 4.371e+11 Mars 4.284e+11 Jupiter 4.187e+11 Saturn 4.737e+11 Uranus 4.284e+11 Neptune 4.412e+11 Pluto 4.660e+11