Obs. : 2014-04-15 Planet Ly alpha (photons/cm^2/sec) Mercury 3.764e+11 Venus 3.737e+11 Earth 4.023e+11 Mars 3.877e+11 Jupiter 3.574e+11 Saturn 4.023e+11 Uranus 3.764e+11 Neptune 3.737e+11 Pluto 3.870e+11