Obs. : 2026-04-23 Planet Ly alpha (photons/cm^2/sec) Mercury 7.098e+08 Venus 7.008e+08 Earth 7.838e+08 Mars 7.098e+08 Jupiter 7.295e+08 Saturn 7.098e+08 Uranus 7.008e+08 Neptune 7.133e+08 Pluto 7.125e+08