Obs. : 2015-12-20 Planet Ly alpha (photons/cm^2/sec) Mercury 4.335e+11 Venus 4.549e+11 Earth 4.433e+11 Mars 4.569e+11 Jupiter 4.534e+11 Saturn 4.492e+11 Uranus 4.408e+11 Neptune 4.356e+11 Pluto 4.335e+11