Obs. : 2017-08-13 Planet Ly alpha (photons/cm^2/sec) Mercury 3.480e+11 Venus 3.663e+11 Earth 3.586e+11 Mars 3.552e+11 Jupiter 3.585e+11 Saturn 3.626e+11 Uranus 3.668e+11 Neptune 3.601e+11 Pluto 3.582e+11