Seriously, I doubt it would even take that long. We get used to shit so quickly, and the news cycles have to keep feeding us new things, the only way we’d keep talking about the aliens if they kept doing new and interesting things. I’d be willing to bet a year later there would be some people who straight up forgot about it. “Oh yeah, aliens! Are they gonna, like, visit at some point or just keep exchanging calls with the Whitehouse?”
Absolutely, but the general populace has so much information thrown at them all day, every day, I really do think most people would just move on from it, because our brains just can’t handle everything all at once. Unless there’s some specific reason to think about it, we’d move on to the things that impact us more directly.
It reminds me of that thing they do on Jimmy Kimmel, where they ask people about fake news stories, and the people invent answers. It’s funny and all, but they do that because it’s considered embarrassing not to know about the whatever the fuck insane thing the news just threw at us, while also there being so much of it that it’s impossible to remember everything. Plus, we’re super suggestable creatures