Obs. : 2012-02-10 Planet Ly alpha (photons/cm^2/sec) Mercury 4.005e+11 Venus 3.990e+11 Earth 3.993e+11 Mars 3.842e+11 Jupiter 4.006e+11 Saturn 3.797e+11 Uranus 3.990e+11 Neptune 4.005e+11 Pluto 4.008e+11