Obs. : 2025-01-20 Planet Ly alpha (photons/cm^2/sec) Mercury 9.824e+08 Venus 9.009e+08 Earth 9.855e+08 Mars 1.002e+09 Jupiter 9.580e+08 Saturn 9.248e+08 Uranus 9.220e+08 Neptune 9.009e+08 Pluto 9.645e+08