Obs. : 2012-08-03 Planet Ly alpha (photons/cm^2/sec) Mercury 3.707e+11 Venus 4.094e+11 Earth 4.355e+11 Mars 4.166e+11 Jupiter 4.141e+11 Saturn 4.166e+11 Uranus 4.283e+11 Neptune 4.377e+11 Pluto 4.384e+11