Obs. : 2010-11-18 Planet Ly alpha (photons/cm^2/sec) Mercury 3.746e+11 Venus 3.723e+11 Earth 3.874e+11 Mars 3.746e+11 Jupiter 3.775e+11 Saturn 3.759e+11 Uranus 3.802e+11 Neptune 3.780e+11 Pluto 3.746e+11