Obs. : 2010-08-10 Planet Ly alpha (photons/cm^2/sec) Mercury 3.727e+11 Venus 3.710e+11 Earth 3.850e+11 Mars 3.710e+11 Jupiter 3.857e+11 Saturn 3.696e+11 Uranus 3.857e+11 Neptune 3.856e+11 Pluto 3.809e+11