Even the solar system experiences decay and some of the planets are further out than they used to be. Apparently. Since sin has affected the whole creation, expecting the sun moon and stars to continue to move at the same rate is kind of absurd, since in such a short time compared to 200,000 years, we have had to switch from a 360 day calendar to a 365.25 day calendar. Much like politicians blaming previous administrations for the amount of money lost without taking into account the depreciation of the value of said money ... so is the concept that we can measure with any certainty at all. There are some things we cannot know, there is a lot of faith placed on the dating methods.