Obs. : 2017-02-15 Planet Ly alpha (photons/cm^2/sec) Mercury 3.336e+11 Venus 3.530e+11 Earth 3.494e+11 Mars 3.549e+11 Jupiter 3.359e+11 Saturn 3.238e+11 Uranus 3.549e+11 Neptune 3.441e+11 Pluto 3.226e+11