Obs. : 2015-10-01 Planet Ly alpha (photons/cm^2/sec) Mercury 4.479e+11 Venus 4.294e+11 Earth 4.209e+11 Mars 4.294e+11 Jupiter 4.371e+11 Saturn 4.759e+11 Uranus 4.277e+11 Neptune 4.521e+11 Pluto 4.636e+11