Obs. : 2015-12-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.564e+11 Venus 4.321e+11 Earth 4.144e+11 Mars 4.316e+11 Jupiter 4.279e+11 Saturn 4.367e+11 Uranus 4.156e+11 Neptune 4.421e+11 Pluto 4.566e+11