Folks don’t hear about it because it is “national security” when the Deep State makes fools of themselves
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Which begs the question how did you hear about it?
There are many former military folks out there who have been telling their stories (often with a request of anonymity) to researchers for decades.
One book as an example:
https://www.amazon.com/Military-Encounters-Extraterrestrials-Real-Worlds/dp/159143324X