Obs. : 2016-03-31 Planet Ly alpha (photons/cm^2/sec) Mercury 4.187e+11 Venus 4.230e+11 Earth 4.206e+11 Mars 4.180e+11 Jupiter 4.184e+11 Saturn 4.168e+11 Uranus 4.187e+11 Neptune 4.206e+11 Pluto 4.160e+11