Obs. : 2016-02-29 Planet Ly alpha (photons/cm^2/sec) Mercury 1.453e+11 Venus 1.453e+11 Earth 1.531e+11 Mars 1.414e+11 Jupiter 1.531e+11 Saturn 1.404e+11 Uranus 1.507e+11 Neptune 1.488e+11 Pluto 1.413e+11