Three steady, red lights were observed at tree-top level in SW sky on an object which emitted NO SOUND.My wife and I, along with my mother-in-law, brother-in-law, and sister-in-law observed three red lights (non-blinking) and in a line, two on the left closer than the third. Object was fairly slow moving, appearing from behind the treeline and disappearing behind the treeline, moving from right to left in the southwest sky. There are significant hills in area, between 1000 and 1200 feet above sea level in our township. While moving, the lights maintained their distance from each other, appearing to be on one object. OBJECT MADE NO SOUND. Approximate distance from our vantagepoint was 1.5 to 2.5 miles.While on phone with local law enforcement, two single engine aircraft were observed in the air, VERY high, and their engines could be heard clearly.