Obs. : 2013-06-21 Planet Ly alpha (photons/cm^2/sec) Mercury 4.218e+11 Venus 4.218e+11 Earth 4.510e+11 Mars 4.344e+11 Jupiter 4.329e+11 Saturn 4.594e+11 Uranus 4.391e+11 Neptune 4.398e+11 Pluto 4.510e+11