Obs. : 2010-12-26 Planet Ly alpha (photons/cm^2/sec) Mercury 3.733e+11 Venus 3.672e+11 Earth 3.683e+11 Mars 3.756e+11 Jupiter 3.743e+11 Saturn 3.691e+11 Uranus 3.743e+11 Neptune 3.766e+11 Pluto 3.769e+11