Obs. : 2015-06-20 Planet Ly alpha (photons/cm^2/sec) Mercury 4.802e+11 Venus 4.620e+11 Earth 4.494e+11 Mars 4.782e+11 Jupiter 4.620e+11 Saturn 4.444e+11 Uranus 4.717e+11 Neptune 4.573e+11 Pluto 4.543e+11