What are these dots on aerial views of Nevada?

For those with Google Earth do these coordinates:
37 degs 38’29.51 N 115 deg 47’58.44 W

What are those green dots–other than a weird game of Reversi? I think they are fields for agriculture or horticulture testing, but a friend of mine says they were painted on to cover something up. I tried looking up The Extraterrestrial Highway website but it gives no mention of them.

Look at 41° 06’ 10" N 101° 01’ 23.79" W for center pivot irrigation arrays in Nebraska.

Linky?

( Hit the “Link to this page” button and copy the URL from the location bar.)

Center Pivot Irrigation

here are some similar ones (along with some other interesting configurations) in Libya:

Yep, that’s irrigation. If you zoom in enough on the ones in Libya, you see some concentric shadows that mark the paths of the wheels as it rotates.

The Libyan ones (at least some of them) are circular reservoirs. We discussed them here; see posts #11 & #20.

Roll the dice in a national forest: http://maps.google.com/?ie=UTF8&t=k&om=1&ll=46.010108,-121.944122&spn=0.02611,0.05785