UFO takeoff in a forest clearing

An ordinary flying saucer takes off, gains altitude and dissolves high in the sky. Maybe you know the technologies that contribute to the creation of a flying saucer? Or what does a flying saucer consist of in your opinion? How is it organized? What type of energy does it use? Do you know sources that describe this aircraft in detail? If you don't know the actual data, then use your imagination and write down your assumptions.