Obs. : 2013-02-02 Planet Ly alpha (photons/cm^2/sec) Mercury 4.082e+11 Venus 3.994e+11 Earth 4.119e+11 Mars 4.171e+11 Jupiter 4.201e+11 Saturn 3.757e+11 Uranus 4.278e+11 Neptune 4.171e+11 Pluto 3.931e+11