Obs. : 2012-09-06 Planet Ly alpha (photons/cm^2/sec) Mercury 4.570e+11 Venus 4.825e+11 Earth 4.438e+11 Mars 3.977e+11 Jupiter 4.877e+11 Saturn 4.004e+11 Uranus 4.647e+11 Neptune 4.515e+11 Pluto 4.108e+11