Obs. : 2013-08-02 Planet Ly alpha (photons/cm^2/sec) Mercury 3.906e+11 Venus 3.923e+11 Earth 3.898e+11 Mars 3.906e+11 Jupiter 3.889e+11 Saturn 3.926e+11 Uranus 3.703e+11 Neptune 3.766e+11 Pluto 3.915e+11