Obs. : 2018-01-25 Planet Ly alpha (photons/cm^2/sec) Mercury 3.427e+11 Venus 3.467e+11 Earth 3.343e+11 Mars 3.325e+11 Jupiter 3.318e+11 Saturn 3.347e+11 Uranus 3.334e+11 Neptune 3.416e+11 Pluto 3.388e+11