Oval Shaped Silvery Metallic Craft moving in a straight line very quickly.

My Mother and I were walking for exercise in the morning.  It was clear out with minimal clouds.  I looked up and saw a silver/silvery white object, oval shaped, gliding in the sky at a high rate.  No sound.  It moved perfectly straight and very fast but seemed like it was gliding and almost weightless.  I pointed to it and my mother saw it also.  We watched it for about a minute.  It was so bright in color (silver) that it almost seemed white.  No windows, pefectly oval, nothing like a plane or jet.  As it moved, it seemed surreal to be seeing this, I had never seen any object in the sky like this before (or since).
Date may be approximate, although the witness does not indicate that fact.  PD