Grass Valley CA, early 80's - Silvery silent slow-flying torpedo-shaped UFO seen over tree-tops.

Recently realized I saw a UFO in the early 1980's and that it wasn't a low-flying, stealth military missile headed for the Pacific Ocean as I had concluded at the time. Was driving slowly on Wiley Lane, facing due north. A silver torpedo-shaped craft flew slowly and silently east-to-west just over the tree-tops, perhaps at 200ft. (Tall pines were growing on either side of the narrow street....appeared to be close to their tops.) There were no markings or windows or obvious sources of propulsion. Don't recall hearing any engine sounds. Was shocked that a military aircraft would be allowed to fly SO LOW over a populated area with the possibility of impacting buildings, tall trees or other small airborn aircraft!!! DISCLAIMER: Date-year is NOT exact (may be off by a year, before or after). Was definitely in spring or summer.
Date is approximate.  PD