Huge green shape-shifting UFO

This was a long time ago and I was a teenager at the time so I had no idea what I saw or that there was anywhere to report it. I’m surprised nobody else has reported (that I can find) because it was directly over the highway. Unfortunately I can’t remember exact date or time, only that it was around dusk, in 1990-1992 timeframe.
I was by myself and driving south on the highway coming around a bend when I saw a very bright green object move slowly over the highway heading from the south to a north west direction. Initially I thought it was a traffic helicopter and then some kind of military helicopter, but as I got closer I saw it was glowing bright green and I couldn’t see the center of it. I kept driving and trying to look at it because it stopped over the Blue Hills Observatory where it appeared to shift from a horizontal shape into a vertical “T” shape.
I don’t know if I need to submit this separately, but I had what I believe to be another incident several years later in 2006 at a remote vacation lake in Maine. I woke up and discovered a small “scoop” circular, completely healed, scar on my calf (which is still visible). I have no recollection of seeing or hearing anything.