This happened the day before Detroit hosted the MLB All-Star game at Comerica Park in 200? I walked out onto our back deck to have a cigarette and saw in the sky three round things in a triangle formation not too far away and not very high up in the sky. It was late afternoon but there was no sun reflection from these craft. They were silvery grey in color but not shiney. I called my wife to the deck so she could see it too. I wanted to run inside and get my camcorder but I did'nt want to miss anything so I stayed on the deck. Soon the orbs started slowly moving and formed a straight line when out of nowhere a larger oval shaped craft appeared. It's rear opend up and all three orbs slowly loaded inside of it. The rear end closed and it started to slowly move ( maybe 50') and poof-it just disappeared. It did'nt fly off it looked like it just flicked a switch and disappeared. The next day we had a B-2 bomber fly overhead and circled back towards Comerica Park (for the All Star Game opening ceremonies). It flew in the same path that the round crafts were at the previous day.