Catalyst: Aug 29

Dr Graham Phillips returns with Catalyst tonight for “Closing in: The Hunt for Alien Life.”

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET – and an answer to this long-pondered question may come sooner than you think.

Right now researchers are hunting for extra-terrestrial life on several fronts. To find out just how close we might be to a breakthrough, astrophysicist Dr Graham Phillips visits telescopes, swims among the stromatolites on the remote West Australian coastline, and chats with scientists from around the world. He even talks to an eminent astrophysicist who suggests we may have already inadvertently stumbled on evidence of alien mega technology out in space.

One of the new alien-hunting fronts is to listen for ET radio messages with an unprecedented new search of the skies. The project is called Breakthrough Listen, and it has a 100-million-dollar budget and will be the most extensive search for extra-terrestrial radio signals ever conducted. And because astronomers have discovered many Earth-like planets in recent years, this new hunt will, for the first time, be able to routinely do highly targeted searches, listening directly to the galaxy’s Earth-like planets for messages.

On a second front, astronomers are starting to study the atmospheres of some of these distant worlds. The kinds of molecules that exist in these alien skies give clues as to whether there’s life on the planet. The task is extremely challenging, but new and extraordinarily powerful telescopes are currently being built, for both on Earth and to be launched into space, that will be up to the task. If oxygen is discovered in an atmosphere, for example, it will almost certainly mean there must be living creatures on that planet. Even more exciting, if artificial chemicals, like CFCs or other industrial pollutants are found in alien skies, it would be a smoking-gun clue that there’s advanced life living on that world.

Another line of attack is to further investigate mysterious radio bursts out in the universe that have been picked up by telescopes in recent years. They’re ten billion times more brilliant that anything we’ve observed before and they last for only a fraction of a fraction of a second. Astronomers have no idea what they are. One eminent astrophysicist has suggested some of them could be the flashes of colossal lasers pushing alien spacecraft around the universe.

Other scientists think the best place to look for evidence of alien life is much closer to home. Our nearest space neighbour, Mars, won’t have intelligent beings of course, but it could be home to simple creatures. In the past, the conditions on our red neighbour were very similar to the conditions on the early Earth. Here, rocklike structures known as stromatolites dotted the coastlines, and the bacteria that created them were some of the earliest lifeforms to appear on our planet. Indeed, these cyanobacteria are so hardy they’ve avoided extinction for billions of years, and still thrive on the remote West Australian coastline. One US astrobiologist believes stromatolites could have once been all over Mars’s watery shores too, and by studying the West Australian stromatolites, he’s come up with a way of looking for fossilised stromatolites on Mars. He hopes NASA’s next Martian rover, due there in 2020, will look for them.

In the end, it comes down to kind of a race: which line of attack will be the first to find evidence of alien life?

8:30pm Tuesday on ABC.