Dr. Robert M. Nelson, senior research scientist at NASA’s Jet Propulsion Laboratory, analyzed pictures of George W. Bush from the first presidential debate much like he would analyze photographs from Mars or Titan to determine surface features. After enhancement Nelson is confident Bush was wearing something under his jacket during the debate “consistent with the appearance of an electronic device worn in that manner.”
In fact, it’s how we measure the depths of the craters on the moon or on Mars. We look at the angle of the light and the length of shadow they leave. In this case, that’s clearly a crater that’s under the horizontal line — it’s clearly a rim of a bulge protruding upward, one due to forces pushing it up from beneath.