It is always nice to lie back and look up into the sky and watch the drifting patterns of clouds. However, some clouds are odder or weirder than others. Some were made by nature and some were made accidentally by the actions of man. As turboprop and jet aircraft climb or descend under certain atmospheric conditions, they can inadvertently seed mid-level clouds and cause narrow bands of snow or rain to develop and fall to the ground, new research finds. Through this seeding process, they leave behind odd shaped holes or channels in the clouds, which tend to be fascinating to see.