Paired blue halos ascend rapidly and silently.

This small event occured whilst I was riding my bicycle home from work late one night around midnight. We lived in the foothills of the Santa Catalina mountains of Tucson, along the southwest slope. I was coming through the trees between two houses to get to my back yard, when I looked up toward our house. The mountains can be seen directly over our roof from that position, about 3-4 miles away. Above the house, but between me and the mountainside were two blue halo-shaped phenomena that rose from about 20 degrees, straight up to about 75 or 80 degrees before winking/fading out. The closest comparison I can come up with is that of the paired exhaust ports on an F-4 Phantom. Two blue flame-like halos trailing to cones as they ascended. They were much larger than jet exhaust ports in scale though, from that distance. They rose above the level of the mountains, from my perspective, and still all I could see were the halos. No shape blocked out the stars where one would think a fuselage would have been. There was no sound whatsoever, and we were very used to the sounds of military aircraft, as Davis Monthan AFB in town is one of the largest AF bases in the SW.
This was no jet. There are no swamps in Tucson to produce "swamp gas".
Date is approximate.  PD