Obs. : 2010-09-07 Planet Ly alpha (photons/cm^2/sec) Mercury 3.550e+11 Venus 3.732e+11 Earth 3.723e+11 Mars 3.732e+11 Jupiter 3.605e+11 Saturn 3.663e+11 Uranus 3.605e+11 Neptune 3.723e+11 Pluto 3.778e+11