Obs. : 2018-03-15 Planet Ly alpha (photons/cm^2/sec) Mercury 3.507e+11 Venus 3.507e+11 Earth 3.451e+11 Mars 3.445e+11 Jupiter 3.445e+11 Saturn 3.445e+11 Uranus 3.488e+11 Neptune 3.478e+11 Pluto 3.445e+11