Yes. Because, as previously noted, not only do the Sun, Moon, and plume need to be collinear (or coplanar, if you prefer), but the imager needs to be close to that plane, as well. Because otherwise, the shadow will be all but invisible.Indigo_Sunrise wrote:IMO, serendipitous image/s, indeed.
![Image](http://www.cloudbait.com/gallery/sky/contrailshadow.jpg)
Certainly, an imager can plan for a shot like this (within reason- at a launch facility, there are simply places where it will be impossible to place a camera). But catching a shadow like this without planning is the very definition of coincidental, or serendipitous.