NASA’s Kepler space telescope, launched in March and returning data since June, gets star billing on “Alien Earths” premiering on the National Geographic Channel tomorrow night at 9 PM Eastern and Pacific time.

Launch footage, animation of the probe in operation as it trails the Earth in a solar orbit, and speculation from researchers about what it will discover bracket an engaging program on the search for extrasolar planets similar enough to Earth to perhaps support life.

The search centers on planets in the so-called Goldilocks zone around stars where conditions are neither too cold nor too hot to sustain life–perhaps not life as we know it, but life nevertheless. To date, gas giants, like Jupiter, have been the focus of the search for extrasolar planets because their large size renders them detectable by ground-based telescopes, mainly via the wobbling they produce in their parent stars.

But the new, space-based telescope should be able to find rocky planets the size of Earth by monitoring the changes in luminosity in stars within its 100,000-star field of view as planets transit in front of them. This is a chore akin to detecting the flickering of a searchlight caused by a moth flying past, according to one of the researchers interviewed in the program.

Another researcher speculates that every star in the galaxy may well host at least one Earth-like planet, which would yield 400 billion such planets all together. Researchers expect Kepler to find at least 50 of them.

It would be an astonishing achievement bringing us one step closer to discovering that we are not alone in the universe, which is why I’m nominating Kepler for this year’s Best of What’s New issue of Popular Science.