As Hollywood depicts it, aliens first make their presence known with giant egg-like objects hanging in the sky, or a massive ship floating above the White House, or a mysterious saucer slowly opening its door on the Capitol Mall. But with the evidence looking more and more like there has to be life out there — very, very far away — a more realistic scenario is that we’ll first learn of alien civilizations through something like SETI that searches the cosmos for radio signals, and not from advanced beings actually showing up here and scaring the bejeezus out of us.

So, let’s say that day has arrived, and we finally detect inarguable evidence of an extraterrestrial civilization. What happens next? The distance will be too great to traverse for the foreseeable future, so it’ll still be just us here, but with a mind-boggling piece of new information. How will we react?

Will we run screaming into the streets? Maybe. But then what? Go back home and make lunch?

Director/Producer Stuart Langfield spoke to Seth Shostak, senior astronomer for the SETI project in California, who’s no doubt spent a considerable amount of time pondering this very question. After all, it’s likely to be him, a colleague, or someone like them who’ll have to break the news to the rest of us someday.

And after years of seeming like SETI was just a fun, quirky project, recent discoveries about the likelihood of there being many planets makes searching the stars for radio signals seem far less quixotic and whimsical.

Ah, yes, what cable news will do with the announcement: Panels of experts arguing, offering guesses disguised as insights, ad infinitum. Until some other story steals our fickle attention away. And we’ll get back to our lives.

But we will be changed. We may not think about it every moment, but we’ll all know something new and profound: We’re not alone.