Oval luminous object traveling north at tremendous speed. Elongated at exceleration. Was not transparent. Sky: unlimited,clear visibility.

My daughter (14) and I were in the front yard talking.  It was 10:30 pm and the sky was absolutely clear with stars evrywhere.  Suddenly my daughter said "what's that". Looking over my shoulder there was an oval light source approx. 30 ft in diameter about 40 - 50 feet above our house. It was not transparent as it blotted out the star field. As soon as both of us were focused on it the object elongated and streaked due north toward Minneapolis (40 mi away). It vanished over the horizon in 2-3 seconds. I served 2 1/2 yrs in the 2d Marine Air Wing and have experience w/aircraft of all types.  This was unknown. At no time did it fall to the earth..but traveled a parallel path w/ the terrain.