Obs. : 2010-06-12 Planet Ly alpha (photons/cm^2/sec) Mercury 3.825e+11 Venus 3.820e+11 Earth 3.660e+11 Mars 3.889e+11 Jupiter 3.795e+11 Saturn 3.896e+11 Uranus 3.795e+11 Neptune 3.710e+11 Pluto 3.674e+11