Obs. : 2024-12-17 Planet Ly alpha (photons/cm^2/sec) Mercury 9.018e+08 Venus 8.647e+08 Earth 8.684e+08 Mars 8.872e+08 Jupiter 8.676e+08 Saturn 8.628e+08 Uranus 8.742e+08 Neptune 8.759e+08 Pluto 8.802e+08