It’s one of the great questions of our age: Are we alone in the universe? A long line of films—from Contact to Close Encounters of the Third Kind to the latest entry, Arrival—have explored whether intelligent life is somewhere out there in the cosmos and wondered what would happen if, or when, we finally come face-to-face with it.

Now, to get the scientific perspective on extraterrestrials, National Geographic has turned to a comedian, albeit one who pursued a Ph.D. in physics. The host of the British TV show It’s Not Rocket Science, Ben Miller has recently published a book called The Aliens Are Coming! The Extraordinary Science Behind Our Search for Life in the Universe.

Speaking from his home in Gloucestershire, England, Miller explains why the TESS project could finally tell us if there is life elsewhere in the universe, how comedy and science connect, and why we will need a new Rosetta Stone to interpret alien messages.

You write in your book that we are living through one of the most extraordinary revolutions in the history of science—the growing belief that we are not alone.

When I was studying at university, we weren’t even sure if there were planets around other stars or whether the solar system might be a one-off. But for the last few decades we have been on this extraordinary voyage where we’ve found thousands of planets around other stars. Strangely, we started looking for planets a long way out because of the technology we had at the time. Now we are starting to look at the stars closest to our own.

Recently, there was an exciting discovery that the very nearest star to us, a red dwarf, has got a planet called Proxima b. Not only that, but the planet is the right distance from that star to have liquid water on its surface. We think liquid water is very important for life. So, right on our doorstep, the conditions might be right for life.