To Find ET, We Probably Need to Think Bigger

It may not exactly roll off the tongue, but Scientific American has coined an acronym to describe a burgeoning field in the hunt for extraterrestrial life, LAWDKI. As in, "Life As We Don't Know It." The idea is that we humans might have to shed our human-centric ideas of what life out there, if it exists, might actually look like. Consider the ongoing search for exoplanets: We keep looking for Earth-like planets (in terms of water, atmosphere, etc.) that could sustain Earth-like life. We also look for biological markers, or chemical "biosignatures," that might signal life in deep space, but those biosignatures are based on our own. What if ET doesn't use DNA or RNA? What if "biology" as we know it doesn't apply? The story by Sarah Scoles digs into all of this, including a new NASA-funded program called the Laboratory for Agnostic Biosignatures.

It aims "to find more fundamental markers of biology, such as evidence of complexity—intricately arranged molecules that are unlikely to assemble themselves without some kind of biological forcing—and disequilibrium, such as unexpected concentrations of molecules on other planets or moons," writes Scoles. "These are proxies for life as no one knows it." It's heady stuff (part of the story deals with the surprisingly complex effort to simply define what life is) and LAB's principal investigator puts things in perspective: “We have these ephemeral lives,” says Sarah Stewart Johnson. “We have this world that’s going to end. We have this star that’s going to die. We have this incredible moment. Here we are: alive and sentient beings on this planet.” And the question of whether life exists elsewhere "feels like an extraordinary thing that I want to know about the universe before I die." Read the full story, or check out other longform stories.)