Obs. : 2012-07-26 Planet Ly alpha (photons/cm^2/sec) Mercury 4.304e+11 Venus 3.981e+11 Earth 4.329e+11 Mars 4.501e+11 Jupiter 3.944e+11 Saturn 4.542e+11 Uranus 3.911e+11 Neptune 4.149e+11 Pluto 4.412e+11