Obs. : 2019-02-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.574e+11 Venus 3.513e+11 Earth 3.475e+11 Mars 3.516e+11 Jupiter 3.494e+11 Saturn 3.513e+11 Uranus 3.516e+11 Neptune 3.553e+11 Pluto 3.407e+11