Obs. : 2013-06-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.218e+11 Venus 4.211e+11 Earth 4.211e+11 Mars 4.291e+11 Jupiter 4.255e+11 Saturn 4.275e+11 Uranus 4.460e+11 Neptune 4.304e+11 Pluto 4.193e+11