You’ll have to download to play it, it’s H265.
Seems a little too bright to be dust, and seems to go too far. Don’t know if I’ve ever seen any airborne stuff in here travel like that. I have seen plenty of airborne stuff though.
And if it’s far away, probably not dust. Too bad the camera doesn’t say the distance.
And if it was recording dust, I’d think it would record all night long.
But who knows what it is. Dust does probably disappear though, like that, once it gets far away or lands. Fluff a pillow in front of the camera, and it will disappear. The dust on it will.