Obs. : 2019-01-26 Planet Ly alpha (photons/cm^2/sec) Mercury 3.507e+11 Venus 3.429e+11 Earth 3.568e+11 Mars 3.542e+11 Jupiter 3.429e+11 Saturn 3.462e+11 Uranus 3.526e+11 Neptune 3.554e+11 Pluto 3.462e+11