Obs. : 2013-02-15 Planet Ly alpha (photons/cm^2/sec) Mercury 4.113e+11 Venus 4.206e+11 Earth 4.125e+11 Mars 4.126e+11 Jupiter 4.115e+11 Saturn 4.267e+11 Uranus 4.126e+11 Neptune 4.126e+11 Pluto 4.277e+11