One of the most common Agrograms is the 4 fold circle formation, it was also one of the first formations to appear in the crop circle lexicon and one the first to appear in the new millennium. The design contains an inner circle and 4 outer orbiting circles, it has appeared and evolved in hundreds of different styles. In addition to representing a signature of carbon based life (Methane), it could also represent the format of 2D, directionality (north, south, east, west) or it could be a reference to the 4 inner planets of our solar system and the sun at the centre.

Astrophysicists are scanning exoplanets for biosignatures (chemical signatures produced by other lifeforms and compositions of exoplanet atmospheres) by analysing chemical signatures captured in light from distant worlds. One of the key elements they are looking for is depicted in this common crop circle pattern. Interestingly the same configuration could apply also for hypothetical silicon based life, so this may more simply be a signature of life in general. Could this be a greeting from a silicon or other based lifeform to us carbon based lifeforms?