Or images of meteors
In 1972, a large bolide streaked across the southwestern USA in broad daylight. It was seen by thousands of people, photographed and even filmed in a number of cases. One of the filmers was a US military satellite. Needless to say, the meteor was not announced in advance, yet many people saw it and real photographic evidence was provided.
I know, any vehicle under intelligent control could easily avoid being detected except by those they want them to see. And then of course no one will believe them.