Obs. : 2010-01-11 Planet Ly alpha (photons/cm^2/sec) Mercury 3.585e+11 Venus 3.651e+11 Earth 3.760e+11 Mars 3.732e+11 Jupiter 3.679e+11 Saturn 3.572e+11 Uranus 3.705e+11 Neptune 3.679e+11 Pluto 3.585e+11