Obs. : 2010-03-12 Planet Ly alpha (photons/cm^2/sec) Mercury 3.625e+11 Venus 3.690e+11 Earth 3.842e+11 Mars 3.822e+11 Jupiter 3.625e+11 Saturn 3.808e+11 Uranus 3.690e+11 Neptune 3.562e+11 Pluto 3.512e+11