It was by pure chance. I was living in a small mountain town in the Western US. Outside on a smoke break. Clear sky, just staring at the stars. One of them moved suddenly in a straight line. Like from zero to whatever speed it was traveling. Then it stopped completely, looking like a normal star.

I stared at it for a few minutes and was starting to think I had imagined it when it moved again, same instant acceleration, but this time in a curved path like tracing a quarter of a coffee mug. Then full stop again.

It performed several moves like this in no discernable pattern. Sometimes in straight lines, sometimes curved. Twice it moved noticeably slower.

Then I got yelled at for taking too long of a break. After work I tried to find it again but nothing moved for the half hour I spent searching.