Obs. : 2013-04-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.354e+11 Venus 4.363e+11 Earth 4.709e+11 Mars 4.354e+11 Jupiter 4.432e+11 Saturn 4.885e+11 Uranus 4.371e+11 Neptune 4.287e+11 Pluto 4.426e+11