Brightly flashing high speed spherical object moving at very low altitude across the mountains, moving sporadically at first.This could be best described as a very brightly flashing spherical/maybe oval shaped light moving about randomly initially. It was actually spotted by one of my supervisors while we were on the tarmac at Ted Stevens not far from the UPS and FedEx parking. When we first spotted it, it was moving about randomly low along the mountain slope in a weird, unpredictable circular pattern like it was pacing a bit before it started traveling across a greater distance and at a slightly faster speed. The unknown object's bright white blinking light moved fast low on the mountains in almost a straight line after about a minute or two, still flashing. The time posted is estimated. It moved far too low and too fast to be any sort of small aircraft or military aircraft, or even a vehicle which might have made the most sense, but even then the light was too bright and flashing too constantly at such a distance, and they generally don't flash that bright while moving either. It covered a lot of ground and seemed to disappear closer to the Cook Inlet by where i live farther south along the mountains towards Girdwood. Note that had it been bright enough or a normal moving flying object i would have seen it past the last visible slope of the mountain chain in the south Anchorage area unless it turned around the bend out of sight. Regardless it seemed way too bright and big for any sort of ground vehicle, and I can tell the difference between small aircraft, helicopters and higher flying jets at night. Unfortunately I was not able to get any videos due to the distance this object was spotted at, nor would the results be good with the camera on my smartphone.