Obs. : 2012-05-31 Planet Ly alpha (photons/cm^2/sec) Mercury 4.674e+11 Venus 4.674e+11 Earth 4.314e+11 Mars 4.748e+11 Jupiter 4.668e+11 Saturn 4.644e+11 Uranus 4.505e+11 Neptune 4.296e+11 Pluto 4.314e+11