File:Moons shodow in muons.gif

Summary
An image of the shadow of the Moon in muons as produced by the 700m subterranean Soudan 2 detector in the Soudan Mine in Minnesota. The shadow is the result of approximately 120 muons missing from a total of 33 million detected in Soudan 2 over its 10 years of operation. The cross denotes the actual location of the Moon. The shadow of the Moon is slightly offset from this location because cosmic rays are electrically charged particles and were slightly deflected by the Earth's magnetic field on their journey to the upper atmosphere. The shadow is produced due to the shielding effect the Moon has on galactic and cosmic rays, which stream in from all directions. The cosmic rays normally strike atoms high in the upper atmosphere, producing showers of muons and other short lived particles.

Licensing
The image is non-free fair use in Muon astronomy.

Fair use for Muon astronomy
The image linked here is claimed to be used under fair use as:
 * 1) it is a scientifically significant photo of a muon astronomy phenomenon;
 * 2) it is of much lower resolution than the original (copies made from it will be of very inferior quality)
 * 3) the photo is only being used for informational/educational purposes.
 * 4) Its inclusion in the article adds significantly to the article because it shows the phenomenon depicted in this article and how it has a significant impact on muon astronomy to the general public.