Agriculture is one of the oldest and most pervasive human impacts on the planet. Estimates of the land surface affected worldwide range up to 50 percent. But while driving through the seemingly endless monotony of wheat fields in Kansas may give you some insight into the magnitude of the change to the landscape, it doesn't compare to the view from above. When seen from space, those same boring wheat fields are transformed into a strange and even beautiful pattern. Some of the most arresting agricultural landscapes occur in the Midwestern United States in areas that rely on center-pivot irrigation (shown at right). The area pictured above near Garden City, Kansas, is being farmed to the point of resembling abstract art or a Magic Eye illusion. Groundwater from the Ogallala Aquifer is used to grow corn, wheat and sorghum in the region. The image above, taken by the USGS' Landsat 7 satellite on Sept. 25, 2000, is a false-color composite made using data from near infrared, red and green wavelengths and sharpened with a panchromatic sensor. The red areas actually represent the greenest vegetation. Bare soil or dead vegetation ranges from white to green or brown. The image below is a simulated true-color shot from the same county in Kansas taken June 24, 2001 by NASA's Terra satellite. Bright greens are healthy, leafy crops such as corn; sorghum would be less mature at this time of year and probably a bit paler; wheat is ready for harvest and appears a bright gold; brown fields have been recently harvested. The circles are perfectly round and measure a mile or a half mile in diameter. In this gallery, we've collected some of the most interesting views of crops from space, including rice paddies in Thailand, cotton fields in Kazakhstan and alfalfa growing in the middle of the Libyan desert. Images: 1) USGS/NASA. 2) USGS. 3) NASA.

Bolivia The star-shaped patterns pictured above are radial soybean fields that are part of a planned settlement east of Santa Cruz de la Sierra in Bolivia. The stars radiate from small towns (shown at right) three miles apart and are separated from neighboring stars by a small stretch of the dry tropical forest that used to cover the area. The image above was taken Aug. 11, 2001 by NASA's Terra satellite. The area has been rapidly deforested to accommodate people that have been resettled from the Altiplano, the high planes of the Andes. Each small community has a school, a church, a bar and a soccer field. The deforestation of the Amazon Basin in Bolivia can also be seen in the false color image below, taken by the Landsat 7 satellite on Aug. 1, 2000. Long paths are the result of logging and large blocks have been cleared for herds to graze. Green, healthy vegetation shows up as red in this image. Images: 1) NASA. 2) NASA. 3) USGS/NASA.

Sudan This interesting arrangement of rectangular fields is south of Khartoum. The crops are fed by thousands of miles of canals and irrigation ditches running from the Blue Nile. The irrigation project was started by the British during colonial times. Fields that are flooded appear purple in this simulated-natural-color image taken by NASA's Terra satellite on Dec. 25, 2006. The area pictured above is a closer look at one piece of the image below. Image: NASA

Brazil Central pivot fields are interspersed with regular grid fields and small streams in this true-color image (above) of Brazil south of the city of Perdizes, taken by astronauts on the International Space Station on Feb. 10, 2011. The crops include sunflowers, wheat, potatoes, coffee, rice, soybeans and corn. The reddish and tan areas are fallow fields. Below is an image of enormous fields in the woodland-savanna region known as the Cerrado in southern Brazil, taken Apr. 16, 2002 by NASA's Terra satellite. Images: NASA

Libya The lonely green circles in this image are center-pivot fields 0.6 miles in diameter in southeastern Libya near the Egyptian border. Known as the Al Khufrah Oasis, the fields are one of Libya’s largest agricultural projects. Virtually no area of Libya receives enough rainwater to grow crops, and the fields here are irrigated with water from an underground aquifer. The image was made by astronauts aboard the International Space Station on Oct. 28, 2004. Image: NASA

The Netherlands The southernmost coastal province of The Netherlands, known as Zeeland (meaning Sea Land), is made up of islands linked by dikes and seawalls that protect the vulnerable agricultural and urban areas. Rivers and estuaries have been walled off from the North Sea to become enclosed lakes. This simulated true-color image was taken by NASA's Terra satellite on Sept. 24, 2002. Image: NASA

Kazakhstan The floodplain of the Syr Darya river in Kazakhstan is an important cotton-growing region for central Asia. In this image, taken by astronauts aboard the International Space Station on Sep. 30, 2010, the active floodplain surrounding the green-colored river is covered with recent meanders that are lined with dark vegetation. In the upper left, an older stretch of floodplain is checkered with darker cotton fields. The crops are watered from canals leading directly from the river and from a reservoir upstream. Image: NASA

Thailand Outside of Bangkok, the landscape is dominated by stripes of narrow rice paddies fed by canals. In this simulated-true-color image, taken Sept. 2, 2001 by NASA's Terra Satellite, the paddies that appear purple have been flooded as part of the growing cycle. Image: NASA

California The Sacramento River Delta is the main drainage for the entire state of California, funneling rain and snowmelt from the Sierra Nevada mountains toward the San Francisco Bay. This inverted delta, where the channeling and river braiding occurs before the river reaches its outlet, has created a fertile agricultural area. Water is pumped through canals to irrigate the fields and serve many cities in the Central Valley. The state depends on the food grown here, but pumping so much water for crops has threatened fish populations, such as the delta smelt, and long-fought legal battles continue over water rights. This image, taken by the Landsat-7 satellite, shows the confluence of the Sacramento (top) and San Joaquin (center) Rivers and the city of Antioch (bottom left). Image: NASA

Minnesota Northwestern Minnesota is dominated by rectangular agricultural fields growing crops such as wheat, soybeans, corn, hay, alfalfa, flax, barley, sugar beets and potatoes. In the true-color image above, taken Sept. 10, 2009 by the Landsat satellite, most fields are green with mature crops. Harvested fields are brown and tan. Farmers in the area use false-color satellite images, like the infrared view of the same area below, to assess the health of their fields and keep an eye on flooding, hail-damage, pesticides and weeds. Images: NASA/USGS

Egypt The Nile river supports a striking swath of agriculture in Egypt. This image was taken by the Landsat-7 satellite on Oct. 19, 2000, after the peak growing season, but the remaining green along with the darker brown soil and scattered grey urban areas show up in clear contrast with the surrounding dry landscape. The line between the two is sharp because the fertile stretch is contained within the walls of the river valley, which can't be seen because the shot was made from directly above the river. Image: NASA/USGS