As I returned from my third solo cross country today, I did a few t&gs. With a huge air show going on at the airport I train at this weekend, there were a lot of cool planes there (experimental & aerobatic). The Thunderbirds just arrived right before I got back and one of them was doing t&gs. As I was on one of my downwinds, he was on final and he let out a bunch of bright white smoke from his tail as he did a low approach. I had a nice view of that. It was awesome!