A friend and I were traveling from Mason City to Ames, IA, on Interstate 35. The sun had set 3 minutes or so before when we both noticed a bright object that we assumed was a jet reflecting the sun (which was now below the horizon). It had a short contrail. It held our attention because it seemed stationary. We then noticed smaller points of light between the first object and the haze hovering above the horizon. From our viewpoint, all were virtually motionless, though one star-like light developed a comma-shaped contrail that went up and arced to the south. One light gradually moved into the low field of scattered cloud and disappeared from view. I counted a total of 7 lights, though only 5 were visible at the same time. They all gradually faded.All lights were the same color as the orange/pink sunset sky, but brighter than the surrounding sky, so we assumed they were reflective. The 3 most visible lights appeared as short streaks, one three times as long as the others. Two were angled up with lower end north and higher end south; the third was angled lower end south and upper end north.The lights were observed west of I 35 as we traveled southbound between mile markers (approximately) 150 - 140. We watched them for at least 15 minutes before the sky grew darker and the last light faded, from about 6:30 - 6:45 p.m.Our first impression of the largest object was of a jet with contrail reflecting the sun, but the object never appeared to move or grow smaller with distance as if it were moving directly way from us. That puzzled us, so we looked more carefully and then spotted the other, smaller lights. The 5 were seen at once, then some faded and 2 more became visible lower on the horizon. I decided to file a report to see if others had noticed, and to see if there's a mundane explanation for what we observed.