Obs. : 2017-02-13 Planet Ly alpha (photons/cm^2/sec) Mercury 3.529e+11 Venus 3.785e+11 Earth 3.679e+11 Mars 3.780e+11 Jupiter 3.618e+11 Saturn 3.434e+11 Uranus 3.780e+11 Neptune 3.775e+11 Pluto 3.476e+11