Obs. : 2013-11-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.249e+11 Venus 4.146e+11 Earth 3.916e+11 Mars 4.091e+11 Jupiter 3.916e+11 Saturn 4.249e+11 Uranus 3.859e+11 Neptune 3.907e+11 Pluto 4.146e+11