Obs. : 2016-02-18 Planet Ly alpha (photons/cm^2/sec) Mercury 4.322e+11 Venus 4.322e+11 Earth 4.001e+11 Mars 4.065e+11 Jupiter 4.036e+11 Saturn 4.141e+11 Uranus 4.092e+11 Neptune 4.308e+11 Pluto 4.286e+11