Obs. : 2024-12-18 Planet Ly alpha (photons/cm^2/sec) Mercury 8.999e+08 Venus 8.773e+08 Earth 8.795e+08 Mars 8.797e+08 Jupiter 8.742e+08 Saturn 8.713e+08 Uranus 8.774e+08 Neptune 8.713e+08 Pluto 8.935e+08