Saucer seen by two individuals over Louisville, KY.

I was driving with one passenger heading eastbound on Shelbyville Road between the Oxmoor Mall and Hurstbourne Lane. The craft was moving north-northwest from the south-southeast from a higher altitude. Initially, we both thought it was an airplane. However, it rapidly descended to around 500-600ft. We thought it must be a helicopter until we noticed there was no noise and - most obviously - it was saucer-shaped with 4-5 white lights around the circumference and one red light on top. Even then we thought maybe it was a drone of some sort; however, the shape does not match and it was much too large to be any kind of civilian drone as this craft was the size of a small to mid-size plane. To my knowledge, the only drones large enough to match this description are military ones. The movement didn't match that of a drone either. This craft moved extremely smoothly - as if it were gliding. The craft hovered for a few seconds over a neighborhood in the Lyndon area,! before heading north a bit, turning back south over the mall, and then westward over the Watterson Expressway before it shot up into the clouds and disappeared.