The sighting was by Scott Waring, owner of UFOsightingsdaily.com and frequent discoverer of objects he calls “100% proof” of ancient aliens. The UFO discovered in the Pacific Ocean is located near the coast of Nazca in Peru and a circular shape can be understood on the seabed.

It is a circle of about 4.2 miles (6.8 kilometers) in diameter, visible about 352 miles (566 km) from the coast of Lima. The circle appears to rise from the seabed like a hill or a mountain. However, this ocean floor bulge is most likely a data artifact. Strange shapes can appear on the ocean floor in Google Earth for many reasons. The company uses data from multiple sources to map the seafloor and these sources have different resolutions or levels of detail, and when put together, strange shapes sometimes appear.

In a 2016 Google blog post, the developers pointed out a quirk in the data that can lead to strange shapes of hills and valleys: The map of the ocean floor is based on a map made by the Scripps Institution of Oceanography, which uses gravity measurements from satellites to roughly map the ups and downs of the seabed.

For more detailed mapping, the company obtains data from ship-based sonar surveys. These sonar surveys send pulses of sound down to the ocean floor and then record the echoes for a high-resolution image. Sometimes the approximate satellite-based measurements and the on-board measurements don’t agree, and a single data point from one or the other can lead to what looks like a steep hill or depression.

In particular, the UFO detected by Waring lies smack in the middle of a transect line where an onboard sonar survey passed, making it possible that the shape is a side effect of joining multiple data sources. These long lines are visible across the ocean floor on Google Earth and are sometimes mistaken for signs of a lost civilization.

The strange shapes of the ocean floor in Google Earth illustrate how little is known about the seafloor. Satellite images covering nearly the entire ocean floor can resolve features down to about 0.9 miles (1.5 km), while modern seafloor sonar can reveal details on the order of 328 feet (100 m). According to the National Oceanic and Atmospheric Administration (NOAA), only 5% of the ocean floor has been mapped by modern sonar.