I was able to see it live on NASA TV. Tremendous watching the roomful of nervous blue-shirted techs hanging on every word from the play-by-play guy as he ticked off every stage -- all the same steps I went through when I played with the Eyes on the Solar System simulation today. And then the room erupting at touchdown. And the first images coming through within a couple of minutes! Amazing.
If you watched the feed closely, there was one blueshirt who fistpumped about a second or two before everyone erupted. He had to have been watching some data feed and knew it was a success just ever so slightly before the rest heard the confirmation.