Obs. : 2011-06-24 Planet Ly alpha (photons/cm^2/sec) Mercury 3.950e+11 Venus 3.992e+11 Earth 4.216e+11 Mars 4.036e+11 Jupiter 4.078e+11 Saturn 4.147e+11 Uranus 4.129e+11 Neptune 4.206e+11 Pluto 4.198e+11