Red, green and white lights flew in, hovered, reversed course to depart. Not airplane or helicopter.I am an amateur astronomer with 50 years of sky watching, thousands of hours, a college degree in Geology. Until now I have never seen anything in the sky that could not be explained as a natural, although sometimes unusual, event.I was out in my yard looking for meteors and relaxing when an object appeared from behind my roof. It was in the SW sky about 15-18 degrees above the horizon, moving to the ESE and caught my attention, initially as an airplane with red, green and white lights over the trees. It was far enough away that the body of the craft was not discernible, due to its bright lights, and it was clearly high in the sky being visible over the trees at the back of my property. I glanced directly at it, and immediately thought there was something very odd, in that the lights were blurry, fuzzy looking. More like orbs than the lights of a plane. There were stars clearly visible nearby that were pinpoints of light so it was just odd in the cloudless sky.The object was visible and moving West to SE slowly for almost five seconds until it slowed quickly and then stopped completely. My first thought was that the object was turning and only appeared to stop but the lights, which were clearly separate colors, were not reorienting themselves as a turning airplane would certainly do. The red and green light did not blink or change intensity. The white light on the right (West) side of the object was pulsating, dimming and brightening, unlike an airplane with strobes that blink. The object appeared to hover for about ten seconds with no other changes in the lights and then abruptly reversed its course back to the NW. The way that it started moving was too abrupt for a turning airplane, it was almost like a computer animation in that it seemed to jump to its path with no curving motion and a very short period of acceleration followed the initial jump. I then maintained a very steady, straight path in departing. I was able to ! change position and watch the object for several minutes. I attracted my wife's attention and she was able to see the object also while it departed NW and disappeared near the horizon.At no time did the orientation of the lights change as I would expect with an airplane. Nor were the lights pinpoints as typical with airplanes. These lights were diffuse orbs that were close enough to overlap. The brightness of the orbs and dark sky did not allow a hint of the actual shape of the object to show.I have always been skeptical of stories told by others about lights in the sky because I had never seen anything that I felt was not "explainable" but this event has made me wonder just what I actually saw. I think that it was definitely not a "normal" aircraft and was obviously a craft under intelligent control. It was an "unidentified" object that I hope others will have reported and perhaps identified as a natural object, but it was NOT something that I have ever seen before.