It's practically a must-have scene in any alien invasion story these days. The UFOs descend, and their passengers already know everything there is to know about the Fonz, Bart Simpson, and Katy Perry's new album. After all, they've been listening to our TV and radio waves for years. But listening in on Earth isn't really that easy — and anyway, it raises the question of why we haven't found the billion-year-old broadcasts of alien sitcoms. TV signals aren't nearly strong enough to remain clear at such vast distances. Instead, to communicate with aliens we'll need to make a concerted effort to broadcast such a signal out into space. Therefore, any extraterrestrial messages that we eventually pick up would almost certainly have been sent on purpose as well.

Actually, Stephen Hawking is working on finding exactly those signals. Breakthrough Listen is a part of the larger Breakthrough Initiative, which is being funded by the esteemed theoretical physicist and Digital Sky founder Yuri Milner. Its mission? To search the skies for suspicious signals that might indicate advanced civilizations. And they've already got a couple hundred targets.

In 2016, the Sloan Digital Sky Survey identified strange frequencies coming off of 234 stars that, according to some scientists, are a sure sign of somebody reaching out. Don't get too excited, though. Those abnormalities may just be a result of human error, or interference from space junk. It's way too early to say that these are aliens. But it's definitely not too early to put the planet's most notable astrophysicist on the case, so that's exactly what Breakthrough Listen is doing.

The Breakthrough Initiative isn't just listening, however. Breakthrough Watch is keeping its eyes open for rocky, Earth-like planets that might support life. Breakthrough Starshot is trying to develop a proof-of-concept model for a starship that could get us there. And Breakthrough Message is offering a million-dollar prize to anyone who can come up with a message to represent the planet Earth (and be comprehensible to extraterrestrials). But if we develop such a message, should we really be sending it?

If something's out there, we definitely want to know about it. The question is, do we want it to know about us? That depends on how optimistic you are about its intentions.

When the Breakthrough Listen Project launched in 2015, Hawking had this to say: "A civilization reading one of our messages could be billions of years ahead of us. If so they will be vastly more powerful and may not see us as any more valuable than we see bacteria." Not exactly somebody you'd want to lay out a welcome mat for.

Of course, his is only one opinion (Carl Sagan and his Golden Record would certainly disagree), but even if we wanted to talk to our interstellar neighbors, we've got to figure out how. While some favor the universal language of math, astronomer Seth Shostak from SETI thinks the answer is linguistic brute force. Basically, hit them with every communication we've got, from math to art to plain old English — in hopes that something sticks. Hopefully we won't insult them, though...you know what? Maybe Stephen Hawking has the right idea after all.