Humans often try to be naive about things they do not understand. Our minds concept of grasping knowledge is why we are visited by the UFOs. They often return to observe our progress here on Earth and keep up with our progress. Abductions of people on to their crafts of unexplained origin, may explain the immaculate conception of the Holy mother Mary. Implanting or in vitro fertilization of the human race is even being done by humans now. Cloning and stem cell research were probably handed down through our alien counterparts.
Look at how fast technology has grown in the last hundred years. We have metals with memory formations and the use of magnetic fields for propulsion and anti matter. These ideas have come from somewhere beyond the boundaries of Earth. The UFO crash at Roswell was the first time the light weight foil looking metal was seen. It had the properties of shaping itself back to original form.
The United States Government used the technology to help in development of stealth technologies and weapons by using reverse technology. Our space program has benefited from the Roswell crash as well. Light weight metals and carbon fibers with added hardeners have produced light weight materials stronger than steel. Fiber optics have been introduced through the space program as well. I think they keep coming back to plant the seeds of knowledge on Earth as well as in our minds. If Ufos were not factual how do we explain our existence in Gods Universe. UFOs may even be the vehicles of angles. Ezekiel saw the wheel, way up in the middle of the air. Could it have been a UFO? You bet!
Cover up by the government to keep the public from panic has been the long lasting excuse our government uses to keep the facts off the table. It would be to dangerous for this type of technology to fall into the wrong hands, even though I would believe the Russians have just as much information or more than the U.S.
People have witnessed UFOs all over the world and even the USO type of crafts that are able to travel at great speeds under water. Man's fascination with objects in the sky has been going on for centuries. Man looks towards the heavens at night and comp templates how he came to be here on Earth. The facts are that we are here on Earth. We were made by a higher being of race that saw good things in us. We were left here to populate the Earth and it is only through the course of UFO visits that maybe the aliens saw our destructive side. This is why aliens stay clear of the human race.