The earthlings sure embarass real extraterrestrial probe designers.
"Some army personnel in Vietnam is perplexed at what they found at the site. There is no clear evidence of any explosion. Metallic parts they found is that of era of US-Vietnam war and has nothing to do with this UFO mid air explosion.
Biochemical UFOs do not leave trace of any nature. Because of their nature and power to bio-disinegrate fast, they do not leave any trace. They travel through wormholes bending space and time. They go across universes through the Hyperspace. They can defy the basic laws of quantum physics. They are propelled by gravity waves. They have the stealth of electromagnetic flux. They are navigated and controlled from parallel universes."