earthstory: A mosaicThis image, taken from the International Space Station in December, shows the gr
earthstory: A mosaicThis image, taken from the International Space Station in December, shows the ground near Alliance, Nebraska.The pattern is created by farmland. The area is divided into squares (40 acres I’m going to guess as that was a standard size when lands were being handed out in the U.S. west) and each one has a circle due to central-pivot irrigation systems. Water comes up a pipe in the center and the irrigation system moves in a circle surrounding it to water crops.If you look closely you can see a linear fabric overlaying the circles, most likely showing the path taken by the equipment during the previous harvest.-JBBImage credithttps://twitter.com/PC0101/status/421047533498949632/photo/1 -- source link