My girlfriend and a close buddy of ours were camping at Chaco Canyon on the night of Friday 10/30/15. We had spent the last few hours of daylight exploring the ancient ruins there, taking photos of the ancient walls/kivas and observing/photographing the many petroglyphs. Around 7:00p we started a campfire, ate, and sat back in our chairs to stargaze before the moon came up. To note, there was no alcohol on-site (not even a single beer, we had actually forgotten to grab anything to drink at the last store/gas station, as we were focused on buying firewood and using the restrooms). We observed satellites, planes, and had an incredible view of the Milky Way, in addition to seeing several shooting stars. At approximately 8:00p, I saw what I thought was another shooting star (streaking from the west/north west to the north/north east), and called out, "shooter!" while pointing toward it. Expecting it to disappear before my girlfriend and friend could react/see it (they initially thought the same thing), what I originally thought was a shooting star (calling out "shooter!" like I always do when I see the flash of a shooting star) stopped on a dime and was apparently a round (or spherical) light (green and white, almost as if it was a fried egg with a green yolk and blurred white rim/border, but all of it was illuminated). It immediately began to slowly descend straight down (from our perspective), then stopped/hovered, disappeared (it may have still been there, but the lights/glow faded into complete blackness), then reappeared a few seconds later in the same spot, held its altitude for a few seconds, and then continued to descend behind a ridge. We have no idea how far away from (or close to) us it actually was, but size-wise, if the middle belt star in Orion's belt was, say, golf ball-sized, then the object that we witnessed (once it stopped...descended/disappeared/reappeared/descended behindthe ridge) was roughly bowling ball sized, relatively speaking. It was also completely silent. The whole encounter, from the time I called out and pointed, thinking it was another shooting star, to the time it ddisappeared behind the ridge was 10-15 seconds. The three of us looked at each other, shocked, as none of us had ever seen a ufo, or anything even close to this before. We didn't see it again, or anything else out of the ordinary, during the balance of the evening..