Obs. : 2017-11-23 Planet Ly alpha (photons/cm^2/sec) Mercury 3.653e+11 Venus 3.578e+11 Earth 3.764e+11 Mars 3.495e+11 Jupiter 3.513e+11 Saturn 3.653e+11 Uranus 3.723e+11 Neptune 3.741e+11 Pluto 3.782e+11