Obs. : 2011-10-11 Planet Ly alpha (photons/cm^2/sec) Mercury 4.141e+11 Venus 4.200e+11 Earth 4.322e+11 Mars 4.262e+11 Jupiter 4.348e+11 Saturn 4.141e+11 Uranus 4.282e+11 Neptune 4.250e+11 Pluto 4.334e+11