Obs. : 2015-01-21 Planet Ly alpha (photons/cm^2/sec) Mercury 4.168e+11 Venus 4.168e+11 Earth 3.814e+11 Mars 4.069e+11 Jupiter 3.887e+11 Saturn 4.158e+11 Uranus 3.964e+11 Neptune 4.069e+11 Pluto 4.216e+11