Ever since ancient people first looked up into the night sky, one question has obsessed humankind: Are we alone—are we the only life in the universe? At last, we're starting to get some answers. From Galileo's handheld telescope to powerful space-based machines that can see for billions of miles; from listening passively for radio wave anomalies to launching active probes to remotely explore distant worlds, the search for life has kicked into high gear, and is already yielding incredible results. Thirty years ago we weren't certain there were any planets anywhere outside our solar system—today we've confirmed literally thousands of them, right here in our own galaxy, many with the right conditions to support life as we know it. Join us for an exciting overview of where we stand in our quest to find extraterrestrial life.
ARE WE ALONE? • On Earth, life is abundant—you can’t keep the mosquitoes out of your yard, or grass from pushing up between your concrete squares. Can all the worlds in the infinite sky be completely devoid of life?
HOW OLD IS TIME? • The building blocks of the universe seem to have appeared in one unfathomable instant. Almost 14 billion years later, humans are starting to unravel the enduring mystery of what happened next.
HOW BIG IS THE UNIVERSE? • Whether there’s life out there depends in part on just how big the universe really is. Whatever you’re thinking: It’s much bigger.
HOW LIKELY IS LIFE OUT THERE? • The universe has been expanding at a tremendous rate for billions of years, creating trillions of stars that are orbited by a functionally infinite number of planets and moons. So…is there life?
WHAT ARE WE LOOKING FOR?
WHAT ALIEN LIFE MIGHT LOOK LIKE • Nobody knows exactly what aliens might look like, but it seems likely that wherever we find it, the laws of physics, evolution, and survival will still apply. And that narrows the options down a bit.
EXTREMOPHILES: NATURE’S HARDIE ST WARRIORS • Earth’s flora and fauna have taught us one thing: When life gets a foothold, it finds ways to survive in all kinds of unlikely places.
HOW WE’LL KNOW WHEN WE SPOT IT • Until the little green men actually come knocking, discovering extraterrestrial life is really all about interpreting data and gradually refining our machines, our techniques, and our best guesses.
THE ALIEN WORLDS IN OUR OWN SOLAR SYSTEM • If we do manage to set foot out there in interstellar space, what conditions will we find? The possibilities are endless…but we can gain some clues from the crazy worlds that exist right here in our own backyard.
OUR ALIEN-HUNTING TECHNOLOGY
SETI: LISTENING FOR COSMIC WHISPERS • The search for extraterrestrial intelligence is a multifaceted international endeavor involving hundreds of scientists and astronomers utilizing some of the world’s most advanced technology.
PROBES: BRINGING EARTH TO THE GALAXY • It’s expensive and risky to send human astronauts gallivanting all over the solar system. But when all you want is a closer look, there’s nothing like a probe, transmitting closeup photos of cosmic wonders back to Mother Earth until the batteries run dry.
TELESCOPES: KEEPING OUR EYES ON THE INFINITE SKY • From the handheld “land ho!” devices of sailors to today’s high-tech, space-based, tennis courtsized behemoths, telescopes have been giving us a closer look for centuries. Take a peek.
HEROES IN THE SEARCH FOR LIFE • Our search for extraterrestrial life has progressed as far as it has thanks to stunning contributions made over the centuries by these standout Earthlings.
SIGNS OF LIFE (POTENTIALLY)
EXOPLANETS: OUR LIKELIEST TARGETS • Take a look at the stars on a clear summer night: We have recently learned that many or most of them have planets,...
