Obs. : 2013-05-24 Planet Ly alpha (photons/cm^2/sec) Mercury 4.528e+11 Venus 4.528e+11 Earth 4.474e+11 Mars 4.607e+11 Jupiter 4.528e+11 Saturn 4.619e+11 Uranus 4.699e+11 Neptune 4.566e+11 Pluto 4.453e+11