News stories usually have a life shelf of a week or two. They'd have to keep adding to it to make it seem like a real distraction if that's what they wanted to do.
I'm sure they'll keep adding to it as long as they think it's a useful distraction.
By the way, for several years I worked on a project that involved writing computer code to analyse sequences of images (videos). The objective of the project was to highlight areas of interest on those images, and extract quantitative data from the areas of interest. I'm sure there's someone in the Pentagon at the moment who is having a lot of fun generating these UFO videos. It's not very difficult. I could do it myself. The basic steps would be:
1. Generate a dark grey background as a canvas.
2. Add a bright triangular area that varies in intensity.
3. Blur the resulting image a bit (hey, it wouldn't be a legitimate UFO sighting if it wasn't blurry!)
4. Find some images of clouds, and superimpose those onto the image.
5. Add some random noise into the image to make it look like it was captured by a camera sensor, rather than generated using computer code.
6. Manipulate the RGB values to add the green tinge.
7. Zoom in and out and add some random shakiness to make it look like it was captured by a handheld camera.
8. Compile a sequence of images generated via steps 1-7 into a video.
All of the above can be done by anyone with a MATLAB licence, and it's not very difficult or time-consuming (if you know what you are doing), because MATLAB contains functions for performing image manipulation operations in its Image Processing Toolbox. For example, the function
imnoise can be used to add noise with a gaussian distribution.
Although there are many steps to create a fake UFO video, when broken down into its individual steps, the process becomes simple. My first objective would be to create a flashing triangle on a dark grey canvas. I would make the dark grey canvas quite large, so as to allow for zooming in and out and adding the shakiness later without risking stepping outside the boundaries of the image.