Very Interesting scene everyone has forgot??

the drawings from all the civilisations with the star maps,holloway clearly says all the drawings are of men worshipping giant beings who are pointing to the stars......... now this proves the engineers came back to earth on numerous occasions as the drawings found were from different civilisations......now im not great with timing so perhaps someone could calculate when these civilisations existed and see if the engineers had visited us before or after there accident on lv-233???