Obs. : 2013-04-19 Planet Ly alpha (photons/cm^2/sec) Mercury 4.866e+11 Venus 4.735e+11 Earth 4.021e+11 Mars 4.825e+11 Jupiter 4.418e+11 Saturn 3.989e+11 Uranus 4.866e+11 Neptune 4.768e+11 Pluto 4.123e+11