2021-12-10 - Knoxville, TN - Triangle

One red light moving switly west to east, becoming 3 red lights in a triangle shape after passing our zenith

Standing in the driveway of a friends house, looking up at the waning moon and Jupiter et al and we both noticed a dim red steady light moving west to east through the planets positions in the sky. We both remarked on it, me thinking it was a dimly lit satellite. That was contested by my friend by saying it was moving too fast and was too low. I quickly agreed with him. I said to keep our eyes on it to see if anything "off" about it happens. When it moved past our zenith, two more dim red lights presented themselves forming the shape of a perfect triangle. My perception was the the two additional lights were obscured by a solid object until our visual angle on it changed enough to reveal them. Watched it as it went out of our ability to see it any longer, about 20 seconds or so. The lights could have been part of one object or possibly 3 separate objects, most likely the former though. Light pollution in our area is horrible. It was about 2k (best guesstimate) in altitude, maybe a bit lower. Speed was faster than commercial craft flying at the same time but not remarkably so. Never acted non-ballistic, was very steady in its course, no deviations. I work at TYS at night and see aircraft all night long and this wasn't one. No strobes or navigation lights. No sound, coasting across the sky like it was on a rail. Could not see a solid shape but could infer one by how the lights revealed themselves to us. Skies were clear, temps cool and no surface wind. Nothing super spectacular about it, just unusual.