Obs. : 2013-03-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.151e+11 Venus 4.528e+11 Earth 4.263e+11 Mars 4.528e+11 Jupiter 4.639e+11 Saturn 4.165e+11 Uranus 4.325e+11 Neptune 4.073e+11 Pluto 3.888e+11