Obs. : 2018-04-06 Planet Ly alpha (photons/cm^2/sec) Mercury 3.543e+11 Venus 3.487e+11 Earth 3.519e+11 Mars 3.535e+11 Jupiter 3.536e+11 Saturn 3.535e+11 Uranus 3.507e+11 Neptune 3.515e+11 Pluto 3.510e+11