Searching for life on Mars
Sarah Stewart Johnson, a planetary scientist at Georgetown University, has written a book, The Sirens of Mars, in which she explores science’s attempts to discover life on Mars
The book is about the search for life on Mars, but it’s not just the science of it; it’s about our human relationship to the planet as well. There were just so many things that were poignant and beautiful and compelling about the endeavour that will never really find expression in the pages of scientific journals. That’s a large part of why I decided to write the book: this idea that Mars deserved a different type of treatment, something that captured the mystery and the wonder, and just of the entire quest.
Why is looking for life on Mars a valuable endeavour?
Even the discovery of simple life beyond Earth really stands to make a tremendous impact. We’ve had these massive advances over the last decades, but biology is still this rather descriptive science. It’s because we have this one data point – we’ve got life on Earth, and we don’t have a second data point. If we found evidence of a second genesis [a case where life arose independently of life found on Earth, rather than migrating between the two worlds], I think it’d be as revolutionary as any breakthrough that’s been made
Do you think it’s possible we’ll hit the point at which scientists can confidently say there is no life on Mars?
It’s certainly possible there is no life on Mars, that we’ll search and search and, like the Moon, we conclude pretty conclusively that that’s it. Who knows what we’ll find, but that’s one of the great things about Mars. It’s accessible, and we have developed so many tools and techniques where we can really do such good science on the planet. We can get there quickly and we can deploy really capable robots to do tremendously sophisticated science on the surface
If there is no life on Mars, what happens next?
Fortunately, there are lots of other targets – even in our own Solar System – that are really exciting to think about. All these other astrobiological destinations, like Enceladus and Europa, and Titan’s a place that we’re really excited about in my laboratory. A lot of our work is trying to imagine life as we don’t know it and how we might detect life forms that are almost inconceivable within the confines of current thinking. in terms of thinking about ourselves and our existence.