I love the sight of those contrails and for this particular photo, it consist another favourite subject of mine -the moon or our Miss Luna ;)
For quick info: those whitish thin-sort-of-lines that appears on the sky is actually a condensation trails by planes (which gives the terms 'contrails'). There are NOT smoke from the engines but it is the result when the heat from the engine/or the exhaust of the plane mixed with the cold air form being at certain level of latitude (it is much a colder temperature at higher latitude which explains why Everest always tops with ice all the year round). In short, that's condensation. Also, for more details could even read from this page here
