Obs. : 2011-06-23 Planet Ly alpha (photons/cm^2/sec) Mercury 4.005e+11 Venus 4.014e+11 Earth 4.228e+11 Mars 4.030e+11 Jupiter 4.058e+11 Saturn 4.161e+11 Uranus 4.081e+11 Neptune 4.194e+11 Pluto 4.221e+11