Obs. : 2017-04-24 Planet Ly alpha (photons/cm^2/sec) Mercury 3.712e+11 Venus 3.703e+11 Earth 3.931e+11 Mars 3.723e+11 Jupiter 3.924e+11 Saturn 3.861e+11 Uranus 3.712e+11 Neptune 3.686e+11 Pluto 3.778e+11