Obs. : 2010-09-28 Planet Ly alpha (photons/cm^2/sec) Mercury 3.859e+11 Venus 3.835e+11 Earth 3.871e+11 Mars 3.835e+11 Jupiter 3.888e+11 Saturn 3.835e+11 Uranus 3.888e+11 Neptune 3.833e+11 Pluto 3.833e+11