Obs. : 2014-06-23 Planet Ly alpha (photons/cm^2/sec) Mercury 4.316e+11 Venus 4.257e+11 Earth 3.669e+11 Mars 3.820e+11 Jupiter 4.269e+11 Saturn 3.675e+11 Uranus 4.047e+11 Neptune 3.912e+11 Pluto 3.737e+11