Reliable people have been seeing the phenomenon known as flying saucers for a thousand years and more. There are good reports as far back as 1500 B.C. and before. Thousands of people have seen some kind of navigable contraptions in the sky, and some have sworn it under oath.
I cannot agree with any astronomer who insists that all of these things are mirages, planets, clouds, or illusions. The majority of the people are articulate enough to tell their stories and sincere enough to make depositions before notaries public. Even scientists concede that these folk saw something.
There is an overwhelming mass of authentic evidence which can be cited as: direct observation, indirect observation, and supporting evidence or indication.