The tech giant has been known to change the so-called Google "doodle" to correspond with holidays and special events -- pumpkins on Halloween, voting booths on Election Day, shamrocks on St. Patrick's Day, etc.
Instead of displaying the letters in the typical blue, red, yellow and green, all of the letters in "Google" (except for the "l") resemble crop circles, the mysterious patterns of flattened crops that have fascinated people for years. The illustration links to a search results page for crop circles.
"Clearly, the situation has escalated since the last occurrence on Sept 5," a Google spokeswoman said. "We're currently in negotiation to restore the Google logo to its natural form. We hope to resolve the situation within the next week."
Although some believe crop circles have extraterrestrial origins, little evidence supports the notion that they are anything other than the work of hoaxers.
But across the Internet, on blogs, comment threads and Twitter, theories about the Google crop circles are swirling.
The most significant clue to emerge came from Google itself. On its official Twitter feed, the company posted the latitude and longitude 51.327629, -0.5616088 and a link to a picture of the new home page logo.
The coordinates tweeted out by Google appear to be the location of Surrey, England, the popular tech blog Mashable pointed out.
According to UFO tracking Web sites, a UFO was spotted on Sept. 15, 1985, by a family in Surrey.
The town of Surrey is also featured in "The War of the Worlds" and the birthday of author H.G. Wells is in six days, on Sept. 21.
Noting that Google's home page also featured an alien-themed image Sept. 5, some wonder if the tech company still has more of the paranormal up its sleeve. On that day, Google's image included a flying saucer that appeared to be abducting the second "o."
A reporter for the U.K.'s Guardian thinks the home page image is hinting at a new product.
"It's almost certainly a viral marketing campaign teasing people ahead of some launch in a week or two," John Vidal wrote. "One possible explanation is that it's trailing an online 'happening' that will coincide with the 143rd anniversary of Wells' birth next week."
Since Google launched its mapping tool Google Earth, scanning the aerial and satellite images for crop circles has become a popular online activity.
Google Earth explorers have spotted crop circles resembling the Firefox logo, Pac Man, a dove and more.