Obs. : 2012-07-27 Planet Ly alpha (photons/cm^2/sec) Mercury 4.120e+11 Venus 3.840e+11 Earth 4.303e+11 Mars 4.461e+11 Jupiter 3.797e+11 Saturn 4.503e+11 Uranus 3.847e+11 Neptune 4.133e+11 Pluto 4.336e+11