Obs. : 2013-12-07 Planet Ly alpha (photons/cm^2/sec) Mercury 3.846e+11 Venus 3.787e+11 Earth 3.983e+11 Mars 4.255e+11 Jupiter 4.045e+11 Saturn 3.920e+11 Uranus 3.961e+11 Neptune 3.940e+11 Pluto 3.792e+11