The origin of life on Earth remains a hotly contested question among scientists. Maybe life began in the depths of the ocean, or with an electric spark, or in a small pond that repeatedly dried. Perhaps the answer to this question will be found through our understanding of the role that RNA played in the evolution of early life, or maybe there are myriad ways for life to start.

Figuring out the source of all life on our own planet is tricky enough, but scientists are also setting their sights on the possibility of the existence of life in space. In this case, we don’t mean Laika the dog orbiting Earth, or human volunteers one day colonizing Mars, but life-forms that originated and organized their own way of life on other planets. While we might not yet know if life exists outside of own biosphere or solar system, in order to discover and identify other living beings in the universe, we must first understand how life itself originates.

When considering the origins (and possibilities) of life in space, there are many complex and interweaving questions to find the answers for. How likely is it that we will find life in space?

How to we even calculate that likelihood?

Where do we look, and what are the best methods to use in our search?

And in the end, whether we find life in space or not, what does that mean to us as a species and a planet?