Obs. : 2018-05-20 Planet Ly alpha (photons/cm^2/sec) Mercury 4.025e+11 Venus 3.911e+11 Earth 3.866e+11 Mars 3.897e+11 Jupiter 3.866e+11 Saturn 3.894e+11 Uranus 4.025e+11 Neptune 3.915e+11 Pluto 3.889e+11