This week on 60 Minutes, correspondent Bill Whitaker reported on unidentified aerial phenomena, or UAPs, more commonly known as UFOs.

Whitaker interviewed two former Navy pilots, Cmdr. Dave Fravor and Lt. Cmdr. Alex Dietrich, who said they witnessed something "unsettling" and unexplainable while flying over the Pacific Ocean in November 2004. Fravor is a graduate of the TOPGUN naval flight program. He was a commander of the F/A-18F squadron on the USS Nimitz at the time of the encounter.

Dietrich, a former F/A-18F pilot, has never before spoken publicly about what she saw that day. 

"It was unidentified. And that's why it was so unsettling to us. Because we weren't expecting it. We couldn't classify it," said Dietrich.

To read more and view the video, click here.