Obs. : 2017-01-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.152e+11 Venus 3.269e+11 Earth 3.119e+11 Mars 3.269e+11 Jupiter 3.120e+11 Saturn 3.152e+11 Uranus 3.157e+11 Neptune 3.269e+11 Pluto 3.248e+11