Obs. : 2014-03-21 Planet Ly alpha (photons/cm^2/sec) Mercury 4.001e+11 Venus 3.988e+11 Earth 4.334e+11 Mars 4.298e+11 Jupiter 4.251e+11 Saturn 4.157e+11 Uranus 4.045e+11 Neptune 4.001e+11 Pluto 3.992e+11