Obs. : 2014-04-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.629e+11 Venus 4.330e+11 Earth 4.091e+11 Mars 4.089e+11 Jupiter 4.339e+11 Saturn 4.108e+11 Uranus 4.411e+11 Neptune 4.144e+11 Pluto 4.079e+11