Obs. : 2009-05-30 Planet Ly alpha (photons/cm^2/sec) Mercury 3.651e+11 Venus 3.556e+11 Earth 3.494e+11 Mars 3.610e+11 Jupiter 3.451e+11 Saturn 3.730e+11 Uranus 3.502e+11 Neptune 3.451e+11 Pluto 3.494e+11