Obs. : 2018-01-11 Planet Ly alpha (photons/cm^2/sec) Mercury 3.488e+11 Venus 3.606e+11 Earth 3.620e+11 Mars 3.482e+11 Jupiter 3.482e+11 Saturn 3.488e+11 Uranus 3.608e+11 Neptune 3.645e+11 Pluto 3.542e+11