Maybe the crop circle symbol is a reference to an upcoming cosmic event on August 21, 2017 when earth, moon, sun and Venus are aligned which coincides with a solar eclipse on the same day?

But what stands out is that the same symbol can be found on the 5,000-year-old Cochno stone in West Dunbartonshire, Scotland, that according to researchers represent an ancient cosmic map.
Source: http://ufosightingshotspot.blogspot.pt

Crop circle footage: https://youtu.be/2NcalNje6UM