Obs. : 2013-10-10 Planet Ly alpha (photons/cm^2/sec) Mercury 4.147e+11 Venus 4.087e+11 Earth 3.940e+11 Mars 3.912e+11 Jupiter 3.948e+11 Saturn 4.147e+11 Uranus 4.011e+11 Neptune 3.947e+11 Pluto 4.018e+11