Obs. : 2020-08-21 Planet Ly alpha (photons/cm^2/sec) Mercury 6.181e+08 Venus 6.541e+08 Earth 6.365e+08 Mars 6.463e+08 Jupiter 6.206e+08 Saturn 6.206e+08 Uranus 6.511e+08 Neptune 6.365e+08 Pluto 6.206e+08