Determining Planet Habitability with Dr. Colin Goldblatt

How do we find life on other planets? A conversation with Project Blue team member Dr. Colin Goldblatt, an Earth scientist from the University of Victoria, to learn more about how to characterize a planet’s habitability.

BoldlyGo SpaceBites: Dr. Goldblatt, first things first. Tell us a little about yourself.

Dr. Goldblatt: Hi, I’m Dr. Colin Goldblatt, and I’m an Associate Professor of Earth System Evolution at the School of Earth and Ocean Sciences at the University of Victoria.

BoldlyGo SpaceBites: What’s your specialty and research focus?

Dr. Goldblatt: My primary research focus is the atmospheric evolution of Earth and Earth-like planets, which is understanding how terrestrial planetary atmospheres evolve. I'm most proud of the breadth of my work: on changes to oxygen, nitrogen and carbon cycles, atmospheric inventories, the climate of early Earth, on snowball Earth and runaway greenhouses, on the theory of habitability.

One of the more exciting things about my research is the interdisciplinary opportunity between Earth System Science and Planetary Science because my work includes understanding the entire range of planets that we can observe. This enables me to leverage what we learn and understand about Earth’s evolving atmosphere, apply it to the study of other planets in our solar system and exoplanets in neighboring systems, and vice versa. By integrating atmospheric and climate science, geology and geochemistry, the kinds of questions I seek to answer include:

How do a planet’s atmospheric composition and climate evolve throughout the course of its history? What are the factors that have been catalysts leading to change? What controls planet and exoplanet habitability? Does life affect planetary evolution? How?

BoldlyGo SpaceBites: What was the path you took to lead you to this research?

Dr. Goldblatt: Before becoming an Associate Professor at the University of Victoria, I was a research associate in the University of Washington Astronomy department and the Virtual Planetary Laboratory (part of the NASA Astrobiology Institute). Earlier in my career, I was a Postdoctoral Program Fellow at NASA Ames Research Center following the completion of my PhD in the School of Environmental Sciences at the University of East Anglia.

BoldlyGo SpaceBites: One of the missions that BoldlyGo is pursuing is called Project Blue, which will put a coronagraphic telescope into low-Earth orbit to search for Earthlike blue exoplanets in the Alpha Centauri system. What excites you about being part of this effort?

Dr. Goldblatt: What’s exciting about that is, if we can locate an Earth-size planet with direct imaging, we would know the color of the planet for the first time because that's something other types of planet finding missions can't do. We would be able to learn from that image whether the planet is: Red Martian like the desert; Bright white like the sulphuric acid clouds of Venus; Grey like the basaltic rock surface of the Moon and Mercury; or blue like the oceans on Earth.

For a scientist like me this would be game-changing because we might discover that Alpha Centauri has one or more exoplanets similar in makeup to the planets in our solar system, or even a potentially habitable planet like Earth.

BoldlyGo SpaceBites: I notice you described finding an Earth-size planet as being potentially habitable.

Dr. Goldblatt: Yes, every time we discover a new planet, people tend to want to immediately ask about life. It’s a natural question. If we find an Earth-size planet that we can actually image, “Is there life?” is definitely going to be the first question a lot of people want to ask. As scientists, we're going to try to explain everything that we can see on the surface or in the atmosphere without invoking “life.” We’ll do this by leveraging everything we’ve learned in studying all the planets in our own solar system. And only when we've rejected every other idea are we going to shout "life!"

Please don’t misunderstand scientific process as lack of excitement. If we become the first people to characterize an Earth-like exoplanet, it would be one of the biggest discoveries in generations, and could redefine our understanding of our place in the universe. It would be the greatest moment of my career, let alone the possibility of eventually being able to rule out every other possibility and yell “life!”

BoldlyGo SpaceBites: Finally, when you are not dreaming about characterizing an Earthlike planet, what else do you like to do?

Dr. Goldblatt: I like to spend time outside, kayaking the coast of British Columbia, trail running, hiking, skiing. I enjoy being in nature here in the Pacific Northwest... Spending time experiencing the natural world of the only inhabited planet we know about so far!

For more information on this topic, check out Dr. Colin Goldblatt’s TEDxVictoria Are we alone? How to find life on other planets.

Dr. Goldblatt is part of the Project Blue Science Team, a BoldlyGo led private space initiative. Read more about Project Blue

Dylan Horn