Some airplanes are graceful, beautiful machines that soar effortlessly through the sky. Others, not so much. Which airplanes ...

Have you got a sharp eye? Put your vision to the test by trying this puzzle, which asks you to spot the plane in the sky. As aircraft tend to be huge, you shouldn't think it would be that difficult.

(WSET) — If you're trying to get a beautiful look ... We are in a flat plane, almost like a pizza," Cerulli explained. "And so, when we look out in our night sky, all of those planets appeared ...

Legends of the Sky: The Liberty Plane is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, Amazon Fire TV, Amazon Fire Tablet ...