 <unk> of transits usually repeat every 243 years . After this period of time Venus and Earth have returned to very nearly the same point in their respective orbits . During the Earth 's 243 <unk> orbital periods , which total <unk> @.@ 3 days , Venus completes 395 <unk> orbital periods of 224 @.@ 701 days each , equal to <unk> @.@ 9 Earth days . This period of time corresponds to 152 <unk> periods of Venus . 
