Obs. : 2010-12-30 Planet Ly alpha (photons/cm^2/sec) Mercury 3.803e+11 Venus 3.768e+11 Earth 3.698e+11 Mars 3.847e+11 Jupiter 3.887e+11 Saturn 3.716e+11 Uranus 3.887e+11 Neptune 3.878e+11 Pluto 3.797e+11