Obs. : 2015-03-21 Planet Ly alpha (photons/cm^2/sec) Mercury 4.680e+11 Venus 4.769e+11 Earth 4.652e+11 Mars 4.771e+11 Jupiter 4.354e+11 Saturn 4.842e+11 Uranus 4.688e+11 Neptune 4.680e+11 Pluto 4.733e+11