Obs. : 2026-08-11 Planet Ly alpha (photons/cm^2/sec) Mercury 7.856e+08 Venus 7.388e+08 Earth 6.853e+08 Mars 8.027e+08 Jupiter 7.851e+08 Saturn 7.551e+08 Uranus 8.023e+08 Neptune 7.471e+08 Pluto 6.608e+08