The mystery's been resolved: Google revealed that the cryptic logos were in honor of H.G. Wells, the famous science fiction author who penned The War of the Worlds, The Invisible Man, and The Time Machine. He was born September 21, 1886 and today would have been his 143rd birthday.
Newt Gingrich, in his book To Renew America, said of Wells, "Our generation is still seeking its Jules Verne or H. G. Wells to dazzle our imaginations with hope and optimism."
Check out the video below for a rare clip of an interview with HG Wells and Orson Welles, and the radio broadcast of War of the Worlds that fooled the US into believing an alien invasion was taking place.