We are at the end of our “Caption This” series. Throughout, you’ve been a tried and true caption contributor. Our last photo features a smiling woman, a clear globe, and some dramatic lighting.

Your captions continued to be clever:

• I can see my house from here!
• And you thought you could hide from me...
• So this is what Earth's core really looks like!
• But how did you shrink it?
• It’s all mine!
• The iPad 1 was ahead of the curve, but the definition of portable is era dependent.
• The world has shrunk, thanks to aviation!
• Hey! Over here! Can't you see me waving from the pale blue dot?
• I see trouble in your future. My star chart crystal ball is never wrong.
• Let's see...if I dig a hole in my back yard to the other side of the world I will end up in Chin… nope, Indian Ocean. Dang!
• What star shall I destroy next?

The truth… The truth is, we’re not really sure what’s going on here. Our best guess is that this was something created for the Civilian Pilot Training Program, and the woman gazing into the globe is a navigation instructor at the university for the Army Air Forces. But, again, this is a guess.

One things that's true is that the past is full of mysteries. Solving those mysteries is one reason our jobs at the Museum are so fun. For this image, we’ll pass the solving, and the fun, to you. Here’s everything we know for sure. The image is from the National Archives and Records Administration. It appears to be a frame from a videodisc with the reference number 342FH-4A-17439-A-25791-AC. In our records, the following keywords are used: Domestic, training, aircrew, navigator, and WWII.

Think you know what’s happening? Let us know in the comments or @airandspace.