Have aliens visited Earth? Some argue that aliens have not only visited Earth, but artifacts from them can be found in the ocean. A UFO specialist claims that a circle visible on the ocean floor in Google Earth is irrefutable proof of alien life.

The circle measures 4.2 miles (6.8 kilometers) in diameter and sits 352 miles (566 km) off

Source: Hot Hardware – This Google Earth Photo Is Sparking Claims Of A UFO Crash And Proof Of Alien Life