The ionized gaseous  tail of any comet is quite large, sometimes extending over millions of miles. Here we see a small  fragment in the center and on each side ionized gas molecules which have spread out over the entire hemisphere of Earth. The atmosphere will absorb these ions, or they will eventually fall to the surface if heavy enough. The lightest ions are farthest away from the fragment since they most affected by the solar wind.  The crop circle is obviously manmade due to its poor construction.

Ken Heck