Crop Circles Go Worldwide Overnight

But last night's crop circles—vast, strange, and often intricate patterns in grain fields—took digital form, as Google's logo morphed into an alien artwork, complete with hovering UFO.

An accompanying Google Twitter post of GPS coordinates sent Web users scurrying to Google Earth software, to discover that the digits denoted Horsell, U.K. (map), site of the first UFO landing in H.G. Wells's novel The War of the Worlds. (YouTube video: Crop Circles on Google Earth.)

The crop circle "Google doodle" remains an unexplained phenomenon, as do some real-world crop circles.

Dawn of Crop Circles

Crop circles first drew attention in the mid-1970s, when they were photographed from the air in fields in the county of Wiltshire, U.K. Made mainly from flattened cereal crops such as wheat and barely, these earliest examples were fairly simple in design.

Since then the Wiltshire region has played host to increasingly an elaborate portfolio of crop circles.

In 2008, for instance, a 150-foot-wide (46-meter-wide) coded representation of the first ten digits of the mathematical constant Pi appeared. And, this summer, a vast and spectacular jellyfish almost engulfed a barley field.