Obs. : 2014-02-02 Planet Ly alpha (photons/cm^2/sec) Mercury 3.850e+11 Venus 3.978e+11 Earth 4.220e+11 Mars 4.072e+11 Jupiter 4.187e+11 Saturn 3.964e+11 Uranus 3.892e+11 Neptune 3.850e+11 Pluto 3.978e+11