zig zag across clear sky covering the full sky in a few secondsClear night sky. Looking out south to east from coast of Tenerife. Just on our balcony of hotel and looking at the clear night sky. Looking at stars and focused on one particular that flickered slightly of which for a second I thought was a satellite. The object then moved in a flash to a point across the sky then stopped for a nano second and changed direction of 90 degrees then back across the sky. Stopped again for a nano second and then across again. This repeated about 6 times in total until out of sight. Every journey to each point must be about 1 second maximum.The best way to describe was that it did a zig zag formation across the sky as if it was plotting motion until disappearing. From the distance I was the object was of a small star. I could not see any detail of the object but could make out a triangular shape. Assuming the breadth of vision on a clear sky overlooking the Atlantic, the difference between each point before zig zag to the next point must have been hundreds of miles so the speed and change of distance was not conceivable of anything I could comprehend.