# what are these circles on google maps? **URL:** \ **Category:** Factual Questions\ **Created:** [April 5, 2009, 6:36pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066 "2009-04-05T18:36:15Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Picard\_Kills\_Kirk](https://avatars.discourse-cdn.com/v4/letter/p/dec6dc/32.png) [@Picard\_Kills\_Kirk](https://boards.straightdope.com/u/Picard_Kills_Kirk)\ **Post date:** [April 5, 2009, 6:36pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/1 "2009-04-05T18:36:15Z")
If you follow this link… [http://www.google.com/maps?f=q&source=s\_q&hl=en&geocode=&q=handle+rd+and+south+ellicott+highway,+colorado&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&ll=38.827874,-104.36574&spn=0.049881,0.077248&t=h&z=14&iwloc=addr](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=handle+rd+and+south+ellicott+highway,+colorado&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&ll=38.827874,-104.36574&spn=0.049881,0.077248&t=h&z=14&iwloc=addr) …It will take you to Colorado. To the right of where the map is centered there are some strange circles designs on the ground. Did I stumble upon the world’s largest crop circle? What are these circles? I should also mention I don’t know anything about farming. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [April 5, 2009, 6:38pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/2 "2009-04-05T18:38:13Z")
[Center-pivot irrigation.](http://en.wikipedia.org/wiki/Center_pivot_irrigation) You can see the boom in most of the circles; in [this one](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=handle+rd+and+south+ellicott+highway,+colorado&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&t=h&ll=38.833874,-104.356685&spn=0.010664,0.016501&z=16), for instance, it’s at about “nine o’clock” on the circle. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [April 5, 2009, 6:45pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/3 "2009-04-05T18:45:39Z")
Missed the edit window — the above link to the detail of the boom doesn’t work. Try [this one](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&t=h&ll=38.833874,-104.356685&spn=0.010664,0.016501&z=16) instead. ---
**Author:** ![Picard\_Kills\_Kirk](https://avatars.discourse-cdn.com/v4/letter/p/dec6dc/32.png) [@Picard\_Kills\_Kirk](https://boards.straightdope.com/u/Picard_Kills_Kirk)\ **Post date:** [April 5, 2009, 7:00pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/4 "2009-04-05T19:00:47Z")
Incredible. I have never heard of or seen anything like this before. Thanks, **MikeS**. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 5, 2009, 7:22pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/5 "2009-04-05T19:22:03Z")
You can see these all through southern Alberta. Have a look at this map: [Google map of some southern Alberta irrigation](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=handle+rd+and+south+ellicott+highway,+colorado&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&t=h&ll=49.780599,-112.437172&spn=0.187549,0.217323&z=12&iwloc=addr). The advantage is mechanical - if you need to irrigate, you either do this, or you build giant rolling sprinklers that traverse the crop. Having a pivoting sprinkler arm is easier to do. The drawback is that you lose the area of the field between the circle and the rectangular boundary of the land. ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [April 5, 2009, 11:22pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/6 "2009-04-05T23:22:38Z")
> [@Sam\_Stone](#): > > You can see these all through southern Alberta. Have a look at this map: [Google map of some southern Alberta irrigation](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=handle+rd+and+south+ellicott+highway,+colorado&sll=38.823945,-104.381142&sspn=1.596252,2.471924&ie=UTF8&t=h&ll=49.780599,-112.437172&spn=0.187549,0.217323&z=12&iwloc=addr). > > The advantage is mechanical - if you need to irrigate, you either do this, or you build giant rolling sprinklers that traverse the crop. Having a pivoting sprinkler arm is easier to do. The drawback is that you lose the area of the field between the circle and the rectangular boundary of the land. Which is 4r[sup]2[/sup] - ᴨr[sup]2[/sup], or 4 - 3.1415926… so somewhat less than 25% but more than 20%. Not an insignificant amount, in other words. ---
**Author:** ![Moonshiner](https://avatars.discourse-cdn.com/v4/letter/m/9fc29f/32.png) [@Moonshiner](https://boards.straightdope.com/u/Moonshiner)\ **Post date:** [April 5, 2009, 11:57pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/7 "2009-04-05T23:57:59Z")
Modern center pivot systems can have corner fill systems. They’re complicated and expensive, so the payback may be questionable depending on crop. > **[Zimmatic irrigation solutions for varying terrain and crops | Lindsay](https://www.lindsay.com/usca/en/irrigation/brands/zimmatic/)** > > Zimmatic is an industry-leading manufacturer of center pivot and lateral move irrigation systems customized to varying terrains, crops and needs. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 6, 2009, 12:03am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/8 "2009-04-06T00:03:56Z")
> [@](#): > > Having a pivoting sprinkler arm is easier to do. The drawback is that you lose the area of the field between the circle and the rectangular boundary of the land. But then, in most of the western US, land is very cheap, and it’s just the water itself and the delivery method that’s expensive. So wasted land that isn’t getting watered isn’t really a big deal ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 6, 2009, 4:31am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/9 "2009-04-06T04:31:33Z")
> [@DSYoungEsq](#): > > Which is 4r[sup]2[/sup] - ᴨr[sup]2[/sup], or 4 - 3.1415926… so somewhat less than 25% but more than 20%. Not an insignificant amount, in other words. Actually it will be less than 20%. Even if you don’t go with the expensive articulating dealie, there’s an end gun with a range of a couple hundred feet that shoots into the corners. ---
**Author:** ![Cyberhwk](https://avatars.discourse-cdn.com/v4/letter/c/7993a0/32.png) [@Cyberhwk](https://boards.straightdope.com/u/Cyberhwk)\ **Post date:** [April 6, 2009, 7:20am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/10 "2009-04-06T07:20:36Z")
There [EVERYWHERE](http://www.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=kennewick,+WA&sll=38.913994,-104.568193&sspn=0.010886,0.027895&ie=UTF8&ll=46.314687,-119.039955&spn=0.30922,0.892639&t=h&z=11) around here. ---
**Author:** ![Cyberhwk](https://avatars.discourse-cdn.com/v4/letter/c/7993a0/32.png) [@Cyberhwk](https://boards.straightdope.com/u/Cyberhwk)\ **Post date:** [April 6, 2009, 7:37am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/11 "2009-04-06T07:37:13Z")
They’re… :smack: ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [April 6, 2009, 10:55am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/12 "2009-04-06T10:55:44Z")
> [@Gorsnak](#): > > Actually it will be less than 20%. Even if you don’t go with the expensive articulating dealie, there’s an end gun with a range of a couple hundred feet that shoots into the corners. Does it water outside the edges of the field? Or is the radius of the arm shorter than half the length of the side? ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 6, 2009, 11:03am UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/13 "2009-04-06T11:03:45Z")
> [@DSYoungEsq](#): > > Does it water outside the edges of the field? Or is the radius of the arm shorter than half the length of the side? I assume it is controlled in such a way that it shoots only into the corners and stops shooting when pointed at the side. It would not be difficult to have a controlled pressure which increases to a max when it gets to a corner and decreases gradually to zero when at the center of a side. ---
**Author:** ![notfrommensa](https://avatars.discourse-cdn.com/v4/letter/n/f14d63/32.png) [@notfrommensa](https://boards.straightdope.com/u/notfrommensa)\ **Post date:** [April 6, 2009, 6:51pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/14 "2009-04-06T18:51:16Z")
Can’t farmers grade the fields so the corners are in low spots so water gravitates to the corners? ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [April 6, 2009, 6:57pm UTC](https://boards.straightdope.com/t/what-are-these-circles-on-google-maps/492066/15 "2009-04-06T18:57:45Z")
Not practically.