Obs. : 2018-03-05 Planet Ly alpha (photons/cm^2/sec) Mercury 3.509e+11 Venus 3.509e+11 Earth 3.538e+11 Mars 3.508e+11 Jupiter 3.520e+11 Saturn 3.503e+11 Uranus 3.494e+11 Neptune 3.492e+11 Pluto 3.500e+11