Obs. : 2015-12-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.499e+11 Venus 4.267e+11 Earth 4.114e+11 Mars 4.276e+11 Jupiter 4.211e+11 Saturn 4.299e+11 Uranus 4.192e+11 Neptune 4.420e+11 Pluto 4.490e+11