Obs. : 2014-06-17 Planet Ly alpha (photons/cm^2/sec) Mercury 4.222e+11 Venus 3.731e+11 Earth 4.029e+11 Mars 4.117e+11 Jupiter 4.327e+11 Saturn 4.041e+11 Uranus 3.642e+11 Neptune 3.828e+11 Pluto 3.961e+11