Obs. : 2017-03-27 Planet Ly alpha (photons/cm^2/sec) Mercury 3.691e+11 Venus 3.680e+11 Earth 3.737e+11 Mars 3.699e+11 Jupiter 3.770e+11 Saturn 3.647e+11 Uranus 3.691e+11 Neptune 3.660e+11 Pluto 3.629e+11