Obs. : 2011-06-16 Planet Ly alpha (photons/cm^2/sec) Mercury 4.267e+11 Venus 4.282e+11 Earth 4.136e+11 Mars 4.282e+11 Jupiter 4.294e+11 Saturn 4.454e+11 Uranus 4.149e+11 Neptune 4.056e+11 Pluto 4.201e+11