Obs. : 2026-02-05 Planet Ly alpha (photons/cm^2/sec) Mercury 8.453e+08 Venus 8.453e+08 Earth 7.951e+08 Mars 8.383e+08 Jupiter 8.036e+08 Saturn 8.135e+08 Uranus 8.035e+08 Neptune 8.135e+08 Pluto 8.383e+08