Obs. : 2019-03-09 Planet Ly alpha (photons/cm^2/sec) Mercury 4.017e+11 Venus 3.974e+11 Earth 3.893e+11 Mars 3.821e+11 Jupiter 3.925e+11 Saturn 3.932e+11 Uranus 3.870e+11 Neptune 4.018e+11 Pluto 3.942e+11