Obs. : 2015-04-30 Planet Ly alpha (photons/cm^2/sec) Mercury 5.058e+11 Venus 5.079e+11 Earth 4.638e+11 Mars 5.026e+11 Jupiter 4.722e+11 Saturn 4.638e+11 Uranus 4.867e+11 Neptune 4.641e+11 Pluto 4.615e+11