There are some very nice things you can spot from a plane. Not only clouds and the ant farms that actually are cities but also atmospheric phenomena. I have seen for the first time a “Glory” on my way to Ireland. On top, a colleague (Peter Hoor from the Johannes Gutenberg University Mainz) took a very nice picture of so-called “Kelvin-Helmholtz instabilities” on a research flight with HALO last week. So I just wanted to show you the pictures here and give you a short explanation on what it is.