Obs. : 2026-09-01 Planet Ly alpha (photons/cm^2/sec) Mercury 7.455e+08 Venus 7.317e+08 Earth 7.275e+08 Mars 7.373e+08 Jupiter 7.407e+08 Saturn 7.268e+08 Uranus 7.454e+08 Neptune 7.267e+08 Pluto 7.282e+08