Obs. : 2015-10-20 Planet Ly alpha (photons/cm^2/sec) Mercury 4.129e+11 Venus 4.237e+11 Earth 4.831e+11 Mars 4.167e+11 Jupiter 4.167e+11 Saturn 4.128e+11 Uranus 4.870e+11 Neptune 4.722e+11 Pluto 4.438e+11