large saucer-shaped object sighted in Wheaton, MD in late 1960's

I'm going by memory, so the date of 5/69 is a wild guess (though it was a warm evening so it was either spring or fall).  I was 8 or 9 years old growing up in Wheaton, MD.  I was visiting a friends house, and for some reason stepped onto his front porch, and overhead was a very large saucer-shaped craft flying silently in a direct line overhead.  I remember bright colored lights rotating around the perimeter of the craft.  I watched in awe as the object just moved silently through the sky no more than 1-2000 feet overhead.  Interestingly, I did not feel compelled to tell anyone about this event.  I don't think I mentioned it to anyone until I was in my 20's.
Date is approximate.  PD