Obs. : 2010-03-18 Planet Ly alpha (photons/cm^2/sec) Mercury 3.729e+11 Venus 3.722e+11 Earth 3.803e+11 Mars 3.787e+11 Jupiter 3.735e+11 Saturn 3.804e+11 Uranus 3.735e+11 Neptune 3.762e+11 Pluto 3.728e+11