Obs. : 2012-06-15 Planet Ly alpha (photons/cm^2/sec) Mercury 4.172e+11 Venus 4.446e+11 Earth 4.488e+11 Mars 4.127e+11 Jupiter 4.446e+11 Saturn 4.180e+11 Uranus 4.565e+11 Neptune 4.543e+11 Pluto 4.483e+11