HAL From United States of America, joined Jan 2002, 2561 posts, RR: 53
Reply 2, posted (12 years 7 months 4 days 11 hours ago) and read 936 times:
Those are irrigation fields. They grow crops in arid conditions, and use a circular water spray arm, with a pivot in the center. The pipe travels on wheels around the pivot, watering the crops, so from the air the field ends up looking circular.
One smooth landing is skill. Two in a row is luck. Three in a row and someone is lying.