Obs. : 2013-04-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.443e+11 Venus 4.501e+11 Earth 4.682e+11 Mars 4.443e+11 Jupiter 4.626e+11 Saturn 4.867e+11 Uranus 4.438e+11 Neptune 4.320e+11 Pluto 4.411e+11