Yesterday morning about 7:00 am there was e very distinct V pattern in the sky over northern Indiana. I have been aware of this occuring all summer. This time I was actuually kind of glad to see it, my girlfriend was with me,she didn't say much but I don't think she could ignore it.
As for distinguishing the difference; Contrails form naturally from jet exhaust,
but dissipate rather quickly.Chemtrails however will stay in the sky for hours giving us the lines and patterns so many have photographed and posted.Also they tend to spread and turn bright blue skies hazy and overcast.
I have done some experimenting with the blasters DTM mentioned and they do seem have some effect,I would warn that one needs to be responcible in their use.