Obs. : 2013-04-14 Planet Ly alpha (photons/cm^2/sec) Mercury 4.383e+11 Venus 4.234e+11 Earth 4.258e+11 Mars 4.234e+11 Jupiter 3.999e+11 Saturn 4.162e+11 Uranus 4.383e+11 Neptune 4.574e+11 Pluto 4.484e+11