Between 11 and 12 o'clock driving west on Ulmerton Rd. My friend and I saw a cloud white rectangle in the distant sky. I watched it cross Ulmerton Rd. at a moderate speed . Because I was driving I lost sight of it. My girlfriend watched it go behind the trees and buildings til it came to a clear area of the sky and it went up until she could no longer see it. What fascinated us was the shape, it was a perfect rectangle as if you took a business envelope and taped it to the sky. The color was the brightest white. It had to be huge because from the distance it was prominent.