We were getting ready for bed in a screened-in area and through the trees saw a large, circular object glowing bright white moving across the horizon to our left. after a second or so, it vanished suddenly. there is no road where we saw it, it's just like empty forest. we had been stargazing around that time and had remarked that mars was clearly visible from where we were. the ufo would have been just to the left of where mars was that night. i love the nightsky app and we were using it to help identify constellations etc. and no crazy aerial phenomena was occurring that night. when we saw the ufo, we had already put away nightsky and were watching a documentary on sharks. i noticed it because it was so bright and we could see a lot of the sky from the screened-in area. we were in this house because we were watching the dogs of the owners until they could get home the next day.