What really made me sit up and look at the sky was the blazing SPEED of what could have been a silvery pointed vehicle--if it was a plane, it was faster than any normal planes. The "con" trail was also unusual. This vehicle would "spurt" pieces of con trail....then no con trail would appear for 3/4 seconds. Again, a con trail would appear, just one power source from what I could see, more con-trail and then nothing again. This happened across the horizon in a matter of seconds. Not a commercial plane for sure. As the vehicle was zipping by across Lake Michigan, it just blanked out--no more con-trail--no more pointed type vehicle.I'd guess the compass course would have been about 220 degrees, not quite straight West--a notch to the South.Amazing speed could have been some type of ram-jet, "if it was a military vehicle.Ben MociniGrandville, Mich.