Obs. : 2017-01-01 Planet Ly alpha (photons/cm^2/sec) Mercury 3.781e+11 Venus 3.713e+11 Earth 3.729e+11 Mars 3.713e+11 Jupiter 3.759e+11 Saturn 3.781e+11 Uranus 3.682e+11 Neptune 3.713e+11 Pluto 3.789e+11