Obs. : 2019-03-17 Planet Ly alpha (photons/cm^2/sec) Mercury 3.572e+11 Venus 3.530e+11 Earth 3.524e+11 Mars 3.438e+11 Jupiter 3.506e+11 Saturn 3.511e+11 Uranus 3.485e+11 Neptune 3.572e+11 Pluto 3.511e+11