We don't know how to identify intelligence over interstellar distances, so what we do instead is use technology for a proxy.

We are made out of stardust. The iron in the hemoglobin molecules in the blood in your right hand came from a star that blew up 8 billion years ago. The iron in your left hand came from another star.

Earlier generations of stars in the galaxy could well have had planets. But really, there was only hydrogen and helium to work with, so they’d all be gas giants and not small, rocky planets.

The existence of life beyond Earth is an ancient human concern. Over the years, however, attempts to understand humanity’s place in the cosmos through science often got hijacked by wishful thinking or fabricated tales.

The space that we're looking through is nine-dimensional. If you build a mathematical model, the amount of searching that we've done in 50 years is equivalent to scooping one 8-ounce glass out of the Earth's ocean, looking and seeing if you caught a fish. No, no fish in that glass? Well, I don't think you're going to conclude that there are no fish in the ocean. You just haven't searched very well yet. That's where we are.

The story of humans is the story of ideas that shine light into dark corners.

SETI is a mirror, a mirror that can show ourselves from an extraordinary perspective and can help to trivialize the differences among us.

Might it be the discovery of a distant civilization and our common cosmic origins that finally drives home the message of the bond among all humans. Whether we're born in San Francisco or Sudan or close to the heart of the Milky Way Galaxy, we are the products of a billion-year lineage of wandering stardust. We, all of us, are what happens when a primordial mixture of hydrogen and helium evolves for so long that it begins to ask where it came from.

Ultimately, we actually all belong to only one tribe, to Earthlings.

We don't know how to identify intelligence over interstellar distances, so what we do instead is use technology for a proxy,