Elixir
Made in America
That's the earliest official detection date. Somehow though, the balloon's track is known at least well enough to show a map of its entire life's journey, from its point of origin in China to its tragic demise over territorial waters off NC.U.S. officials first detected the balloon and its payload on January 28 when it entered U.S. airspace near the Aleutian Islands.
Maybe someone is trying to tell China something. Or maybe someone is just making shit up, But I'd bet that hordes of these things are known to US intelligence, and most are probably detected routinely upon or shortly after their launch. If that is the case, it is of course to the US' advantage to refrain from giving away that capability, though I'm sure Trump (if he was in office) would let it slip if he thought it would improve his image for one 2-day news cycle.
Chinese probably got much more intelligence information on any trip they made to Mar-a-Lago by just listening to the blowhard bragging, or looking around for stray papers
^^^ THAT