Hi. I’m Jim Green, NASA’s chief scientist and your host on NASA’s podcast Gravity Assist.

You know, life on Earth is just about everywhere we look – from the depths of the ocean to even the Antarctic Tundra. Here on Earth, we find that against all odds, life survives and thrives. But what do we know about life beyond Earth? Are we alone?

Life on Earth just occupies a teeny portion of all of time. To me, life seems so inevitable and the universe is so broad and vast, that I can’t imagine that we would be alone in all of that space. If we’re the only game in town, it’s an awful waste of space. We do not know if there is life beyond the Earth. You just have to search and search.

If you’ve ever wondered if there’s life out there beyond our planet, you won’t want to miss this season’s Gravity Assist. In each episode, I’ll be talking with scientists that specialize in the field of astrobiology. I’ll be asking them, “How do we define life? What is life anyway? What do we know about how life got started here on Earth and how it developed in this beautiful complexity that we see today? What could life be like beyond Earth and how do we look for it?”

So there are a lot of wild and crazy places that we could search for life. The moons of Saturn and Jupiter are so compelling- Ganymede,Titan, Europa, Enceladus. Life might have existed on Mars in its past and might even exist there today. On exoplanets, because there’s a lot.

On average, there’s an exoplanet for every star in the sky and for every 10 stars there’s one that might have liquid water oceans. Advancing the technologies for one helps us look for it in any place that we might be looking. Here at NASA, we have a fleet of spacecraft going out into the solar system and beyond and a lot of fabulous scientists that are piecing together this puzzle from the observations these missions make.

Join me on this journey to find out what’s out there. Tune into gravity assist wherever you get your podcast. Download at: nasa.gov/gravity-assist