[r9etb]

Makes sense to me. A friend of mine is a sexton for many of the local cemetaries and he swears there are predicable tides in the earth. He says the best time to backfill a grave is at “low tide” because he can get more earth back into the hole.

Precise orbit predictions (among other things) take account of solid tides, which are a slight bulge of the Earth in response to lunar and solar gravity. It's not a huge effect, but it matters.

I could see your friend's story being right; and this article makes sense in that context.

[cripplecreek]

Its not a big difference but enough for someone with nearly 30 years of experience to recognize.