Obs. : 2010-06-20 Planet Ly alpha (photons/cm^2/sec) Mercury 3.815e+11 Venus 3.886e+11 Earth 3.773e+11 Mars 3.974e+11 Jupiter 3.650e+11 Saturn 3.981e+11 Uranus 3.650e+11 Neptune 3.703e+11 Pluto 3.800e+11