Crop circles have been appearing for hundreds of years. But they became very commonly known more recently, when they started to make lots of newspapers. Farmers were waking up and finding really intricate patterns in their fields. Like this: and this:
At the time, there were lots of hypotheses about why this was happening. Lots of people said, “OH! ITS THE ALIENS!” But there was never any proof or evidence of aliens landing. Other people speculated that it might be wind blowing in special ways (Um, seriously?! That would have to be some pretty clever wind.)
But now, most people agree that it was actually some VERY tricky humans, sneaking out into fields at night doing it. And it didn’t take very complicated equipment at all! Just a wooden board to stamp down the plants, with some rope that they held onto (here’s a guy holding one: )
What I think IS really cool about the crop circles, is that although the things people have used to make them are really simple (like in the photo above), the mathematics and planning required to get some of the very exact, special shapes is actually quite complicated – and involves some very tricky geometry!
eileen is right. This was a really popular hoax about 10 years ago. It was all over the news, and all the hippies were saying “the aliens are coming”. Turns out it was mostly groups of young people having a laugh and making very elaborate patterns in the fields using wooden planks tied to their shoes at night!