Rachel L. Harris, Ph.D.

About Me, More or Less

When people ask what I do for a living, I usually say that I wear many hats. I am an astrobiologist, microbial ecologist, biogeochemist, scientific strategist, program manager, and – when the situation demands it – professional cat herder. I currently serve as a NASA Postdoctoral Management Program Fellow in astrobiology at NASA Headquarters and as a research associate in the Girguis Lab at Harvard University. I realize having two titles does not exactly simplify things. It is not an identity crisis, I swear.​

My work sits at the intersection of life, environments, and evidence: how life persists under extreme conditions, how it transforms the worlds it inhabits, and how it leaves traces that might be recognized elsewhere. As a researcher, I study the biogeochemistry and ecophysiology of microbial life in extreme environments, with a particular interest in anaerobic methane cycling in the deep subsurface biosphere, its role in the global methane cycle, and its relevance to biosignature detection in astrobiology. ​In planetary science, people often identify with a particular kind of world. I will be the first to admit that I am a Martian at heart. I have supported Mars exploration and Mars Sample Return through NASA-facing and community efforts, including the Perseverance rover landing site selection process and the joint NASA–ESA Mars Sample Return Campaign Science Group, where I served as Strategic Science Communications Chair. But what excites me most about the search for life is that every mission, even to seemingly inhospitable worlds, can sharpen how we think about habitability, evidence, and life elsewhere. I am especially drawn to work that breaks down silos, brings unlikely communities into the same room, and builds shared scientific frameworks across disciplines.​

That brought me to NASA Headquarters, where I coordinate the development of the NASA Decadal Astrobiology Research and Exploration Strategy, NASA-DARES. NASA-DARES is a first-of-its-kind, community-informed effort to help guide the future of astrobiology across NASA Science. In practice, this is where my tendency to wear many hats shines: I help support strategic planning, manage end-to-end task force activities, design community engagement processes, synthesize scientific input, and communicate about the effort with external stakeholders ranging from the public to the National Academies’ Space Studies Board.​My path into this work began long before I had words like “astrobiology” or “biogeochemistry” for it.

As a kid, I was the sort of person who dug up the backyard vegetable garden, searched for fossils at recess, and assumed the natural world was full of clues if I looked closely enough. Looking back, I never really stopped asking the same kinds of questions: What happened here? What lived here? What evidence did it leave behind? Could we find evidence like it somewhere else?​

More broadly, I am interested in how science becomes public purpose: how institutions, communities, and long-term vision can help us pursue questions that are bigger than any one project or discipline. Across my research, strategy, and service work, I keep returning to one question that is scientific, philosophical, and deeply human: Are we alone in the Universe?