I'm not aware of a "special" regio Earth crosses every 1470 years .
As Earth orbits the sun every year I would expect a yearly cycle .
There are some theories the activity of our sun may be involved :
http://www.uni-heidelberg.de/press/n...5/2511ice.html

In addition : I looked which long period comets are known . Most of them are short period comets . The longest period I find in the list is the comet 153P/2002 having a period of 364 years .
http://pdssbn.astro.umd.edu/comet_da...ic_comets.html
Concerning the asteroids : the NEA database shows that the near earth asteroid 1999X535 has a period of 74 years . No asteroids are known with longer periods .
So I don't get any link to bodies appearing or colliding with the given period of time .
Of course as the latest impact out of your diagram is already a good while ago , these bodies may exist but out of our detectable range as they may be now residing far away and out of our optical reach .

If such bodies exist they must have a semi-major axis of about 130 AU , far beyond Pluto's orbit , giving a period of ca. 1480 years .

Finally , one might also think having a (not yet detected - and therefor hypothetical ) disturbing planet in our solar system having a period of 1450 years ( also 130 AU SMA) which brings it twice through the Kuiper belt per revolution. This body could scatter the KBO ,throwing them into orbit towards the sun . Problem with this hypothesis is that the scattered objects fly off in every direction and soon loose their orbital characteristics concerning their period. They would arrive at Earth at "random " intervals....