Obs. : 2015-12-21 Planet Ly alpha (photons/cm^2/sec) Mercury 4.390e+11 Venus 4.582e+11 Earth 4.443e+11 Mars 4.576e+11 Jupiter 4.520e+11 Saturn 4.560e+11 Uranus 4.449e+11 Neptune 4.379e+11 Pluto 4.432e+11