Obs. : 2015-04-23 Planet Ly alpha (photons/cm^2/sec) Mercury 4.829e+11 Venus 4.874e+11 Earth 5.163e+11 Mars 4.796e+11 Jupiter 5.196e+11 Saturn 5.163e+11 Uranus 4.824e+11 Neptune 4.824e+11 Pluto 4.884e+11