Obs. : 2013-05-17 Planet Ly alpha (photons/cm^2/sec) Mercury 4.520e+11 Venus 4.520e+11 Earth 4.504e+11 Mars 4.613e+11 Jupiter 4.474e+11 Saturn 4.376e+11 Uranus 4.578e+11 Neptune 4.441e+11 Pluto 4.505e+11