Obs. : 2017-12-26 Planet Ly alpha (photons/cm^2/sec) Mercury 3.659e+11 Venus 3.668e+11 Earth 3.602e+11 Mars 3.658e+11 Jupiter 3.658e+11 Saturn 3.668e+11 Uranus 3.556e+11 Neptune 3.583e+11 Pluto 3.679e+11