Obs. : 2011-04-12 Planet Ly alpha (photons/cm^2/sec) Mercury 4.534e+11 Venus 4.561e+11 Earth 4.185e+11 Mars 4.534e+11 Jupiter 4.534e+11 Saturn 4.185e+11 Uranus 4.578e+11 Neptune 4.611e+11 Pluto 4.329e+11