Obs. : 2018-04-03 Planet Ly alpha (photons/cm^2/sec) Mercury 3.462e+11 Venus 3.366e+11 Earth 3.427e+11 Mars 3.447e+11 Jupiter 3.445e+11 Saturn 3.447e+11 Uranus 3.400e+11 Neptune 3.449e+11 Pluto 3.429e+11