Crop Circles....Retrospect?

ETs cannot come here, no intelligent life at other planets of our solar system, nearest extra-solar planet at Epsilon Eridani, our fastest rockets require 7200 years travel there, Sid Deutsch calculate no advanced civilization require less of 210 years travel such great distance, is unfeasible expect any life form travel centuries just make crop circles, several sources show people make complex crop circles quickly, some pranksters may make patterns at daytime but tell of them later, you not know how long require make them or when make them, you have confirmation bias, is no good reason say ETs make crop circles, they cannot come here and earthlings can make all crop circle patterns.