Have you ever been waiting in line at the airport waiting to go through security and wondered whether or not TSA agents can see you naked when you go through the scanner? The answer is actually a lot more complicated than a simple "yes" or "no" answer. 

Luggage Scanners 

Before we go into how TSA agents scan you, we first need to take a look at the types of scanners agents use. For scanning luggage, security personnel in most airports use a cabinet x-ray system. This system comprises of a conveyer belt that reel passenger personal items into an enclosed cabinet and out on the other side. The moving conveyer belt stops inside the box, where ionizing X-rays (which are harmless once they've passed through your luggage) are shot through the item being scanned. 

During scanning, an image is produced that gets displayed in front of a specially trained TSA agent, who scans the image for any suspicious items or technology that could be hidden inside the piece of luggage. If the item is clear of any potentially hazardous items, the agent will move the item out of the scanning machine and out the other side. The flaps at each end of the machine actually have a very important purpose in keeping ionizing X-rays from escaping the scanner. 

Passenger Scanners 

While TSA and other security agents can see the inside contents of your luggage, can they actually see the inside contents of you? The answer is partly. A backscatter passenger scanner is the machine that you have to walk through and stand in for a few seconds before moving on. It allows TSA to scan underneath your clothes and check for any potentially suspicious items. These machines work by passing beams of very low energy X-rays through you that reflect off the other sides of the machine and back through you.

The point of this is to see if the X-rays inside of the machine will reflect off anything other than your skin, such as a metal item. This is why it is crucial that you remove all metal items from your pockets and hands, along with your shoes. All a security officer will see in your X-ray picture is a gingerbread looking form, which is supposed to be your skeleton, as this is the only dense part of your body that can reflect X-rays besides your skin or other objects such as metals or plastics. Most backscatter X-ray scanners have it so that there is a generic map of a human rather than a molded map of the subject being scanned, and if the machine sees something suspicious on you, then it will mark the part of the generic human figure. 

Newer machines, known as full body scanners, do create an actual 3D image of the subject being scanned, but these aren't in wide use. The images produced from full body scanners are better at producing a more thorough and comprehensive image. Most of the time, these new scanners are only used as an extra precaution if someone of suspicion has been identified and needs to be inspected further. 

So, if you are ever wondering what a TSA agent sees on the other side of that scanner, just think of your skeleton at worst. Or at best, a vanilla gingerbread cookie.