Obs. : 2014-12-06 Planet Ly alpha (photons/cm^2/sec) Mercury 4.188e+11 Venus 4.168e+11 Earth 3.865e+11 Mars 4.130e+11 Jupiter 4.060e+11 Saturn 4.235e+11 Uranus 4.010e+11 Neptune 4.089e+11 Pluto 4.148e+11