Obs. : 2010-03-28 Planet Ly alpha (photons/cm^2/sec) Mercury 3.901e+11 Venus 3.863e+11 Earth 3.678e+11 Mars 3.667e+11 Jupiter 3.786e+11 Saturn 3.658e+11 Uranus 3.877e+11 Neptune 3.694e+11 Pluto 3.653e+11