[John H K]

The Pacific ocean was left as the remnant of the loss of mass, Pangea (single land mass) the bulge at the opposite side of impact

The moon is much older than the Pacific.

And there have been MULTIPLE "single land masses" on earth. There was Rodinia, which was a single land mass that split up scattering continents everywhere, then those continents came together to form Pangea. There may have been ones before Rodinia but Rodinia is the earliest one we can reconstruct well.

[Mr.Atos]

Apologies for the over-simplification... and, I appreciate the correction. I am aware of the on-going movement of land-masses (Prior to Pangaea). The theory that I have heard suggests the crust on the pudding has been moving around ever since that impact. It was a thin theory then, and likely still is (No pun intended). But, the more we learn about 'planet-killers' the more believable it becomes.