Obs. : 2018-03-31 Planet Ly alpha (photons/cm^2/sec) Mercury 3.462e+11 Venus 3.438e+11 Earth 3.465e+11 Mars 3.495e+11 Jupiter 3.487e+11 Saturn 3.495e+11 Uranus 3.438e+11 Neptune 3.542e+11 Pluto 3.511e+11