The model craft was loaded on to a truck by thieves last Saturday before being dumped in nearby woods.
The space agency will be testing out its futuristic Mars landing system over Hawaii this week.
An experimental saucer-shaped vehicle designed to be used on Mars has undergone a successful test flight.
Amateur pilot Kenneth Arnold kick-started the modern UFO phenomenon after a sighting back in 1947.
Retired engineer Duan Phillips has spent the last 15 years constructing a saucer-shaped flying vehicle.
The space agency is preparing to test a new vehicle that is designed to help astronauts explore Mars.
Iran has built an unusual new craft that has been described as "the world's first flying saucer".
Russia are embarking on a 5-year program to construct a series of "flying saucer" style flying vehicles.
Anthony Bragalia explores the connection between V-2 tests in the 1940's at White Sands and UFOs.