Obs. : 2016-04-15 Planet Ly alpha (photons/cm^2/sec) Mercury 4.234e+11 Venus 4.243e+11 Earth 4.221e+11 Mars 4.197e+11 Jupiter 4.281e+11 Saturn 4.168e+11 Uranus 4.243e+11 Neptune 4.191e+11 Pluto 4.123e+11