An Aircraft Engineer, A Pilot and a Scientist are together New Year's Eve ( the three of us don't drink) and the Scientist looks up at approx elevation of 70deg and points out a very bright light that stands out from the stars in the North and calls it as a satellite. We all look up, and as we do, the "satellite" begins moving faster and then stops dead in the sky at relatively 90deg elevation above us but continued to move, stop and flash; which was a continued pattern for approx 1/3 of the sighting. We kept watching it, somewhat flabbergasted. We followed it for 23 minutes total as it continued to move at rediculous breakneck speeds, so much so that the light it was emitting was blurred behind it as it went (we did the math at the time and estimated some moves were made at least at Mach 3-4 possibly higher!!...but with not a single sound). It remained mostly in a NE bearing as It continued making seemingly impossible stops, right angle turns, arcs, moving in all directions at some point but it was moving in 4 dimensions; in that it was not just moving up, down, left, right; but diagonally also. It would stop, move up (what seemed like) a few hundred meters then move parallel to the line it just made back in the opposite direction! (Like playing a game of snake) At times it looked like it was trying to hide amongst stars. The last time we saw it it literally faded away. We continued to look diligently for it but to no avail. It seemed intelligent; playful almost. It was not a plane, as we were near a regional airport and saw a plane pass as we were watching (which gave us a good reference point, but we were all very used to seeing planes land, takeoff and familiar with flight patterns/lights). We saw another plane not long after "it" "left". It was very strange indeed. It is something that has stuck with me and something I will never forget and something Iwill forever ponder I guess. What it was doing goes against/defies everything I know of physics. Thank you for the opportunity to share my story with a willing ear. Kind regards.