Abt 30 objects with one white light evenly spaced, traveling slowly at high altitude in a line over the course of about 20 minutes

Tonight at approximately 10 pm I stepped out on my porch to look at the stars, when I noticed two "stars" evenly spaced moving across the sky, then another, then another, in what appeared to be slow flying, high altitude crafts, all evenly spaced apart, heading in a straight line toward the north east.  I called my husband after I witnessed about 8 of them, and he joined me on the porch.  We watched at least another 5 or 6, appearing one at a time from the south west, evenly spaced, traveling at the same speed, and disappearing in the north eastern sky.  My husband went back into the house, and I grabbed my phone to call my brother who lives about 5 miles away.  He stepped outside and together, we watched them come again and again.  That phone call lasted about 10 minutes, we saw at least another 6 together.  I needed to know I wasn't alone in seeing these.  Very strange and a bit scary.  They subsided at approximately 10:20 pm.  I have written to Wood Tv 8 and to Gerald R. Ford International Airport to see if I can get an explanation of what these air craft might have been, and am awaiting a response.