Obs. : 2017-02-04 Planet Ly alpha (photons/cm^2/sec) Mercury 3.221e+11 Venus 3.139e+11 Earth 2.977e+11 Mars 3.139e+11 Jupiter 2.977e+11 Saturn 3.036e+11 Uranus 3.067e+11 Neptune 3.236e+11 Pluto 3.221e+11