Atlas V rocket launch in Florida, from either Sept 2014 or Sept 2015.
The reason why this is 'normal' and 'not normal' at the same time is that it is basically something mundane (the Atlas 5 rocket launch from 2015), BUT the atmosphere's composition has changed over the last couple of decades or so, which means that things travelling through it often produce weird contrails. Climate change is real (and no, it's not man-made).