As it turns out, the agency's Orion capsule -- which was successfully shot around the moon over the past 25 days or so, unmanned -- was plastered with 5 different symbols meant to serve as brain teasers for the general public ... and perhaps alien life too?

These images amounted to either drawn pictures, codes and even music -- which were scattered inside the capsule ... albeit, somewhat discreetly.

First off, NASA stuck a rendering of a red cardinal above the pilot seat's window ... meant to honor former Orion program manager Mark Geyer, who died in 2021 and who loved the St. Louis baseball team. There was also a Morse code depiction inside, spelling out Charlie and representing another ex-Orion program manager, Charlie Lundquist, who died in 2020.

There were also country codes found in Orion -- a nod to the nations that came together to help build it ... including the U.S., Germany, Switzerland, Sweden, Belgium, Italy, Norway, Spain, Denmark and the Netherlands.

Another hidden nugget ... the letters "CBAGF," which are said to be the notes to Frank Sinatra's "Fly Me to the Moon."

Finally, there's some binary code in there too -- shown in black and white blocks -- which translates to the number 18 ... signifying the next Apollo mission that they're hoping to pull off after Apollo 17. Remember, the whole point of this thing is to get astronauts back to the moon by 2025 -- and with Artemis now done, we're one step closer to doing that.

You'd need to know some deep NASA trivia to nail those hidden clues, but there ya go.