Obs. : 2015-04-15 Planet Ly alpha (photons/cm^2/sec) Mercury 4.724e+11 Venus 4.616e+11 Earth 4.862e+11 Mars 4.694e+11 Jupiter 4.498e+11 Saturn 4.974e+11 Uranus 4.765e+11 Neptune 4.905e+11 Pluto 5.151e+11