AMA: Lisa Pratt, NASA Planetary Protection Officer

Your new gig basically involves protecting Earth from aliens. How competitive was the application?
I had often thought about what a remarkable thing it would be to be in that position. Applying for it was a long shot, though—I’ve been told there were 1,400 résumés.

What do you think set you apart?
I had a combination of the right technical background and a reputation for being someone who could seek consensus on complex problems, which is really what planetary missions are all about. They’re hard to do not only in terms of rocket science, but also in terms of not contaminating a place that might be habitable, and then not bringing something back that might be harmful to life on Earth.

There was a really short turnaround time—the position was posted at the end of July 2017, and applications were due a couple of weeks later. Did you have to think about this for a while, or did you apply as soon as you saw it?
I waited until about 48 hours before the position was closing. And even then, it was only to get my 23-year-old daughter to stop bugging me about it. She and my husband both kept saying, “You’ve always talked about this, and we’re getting tired of hearing it. Why don’t you apply?” As a fairly senior researcher in an associate executive dean position at IU, I was really hesitant. I thought maybe the time for this kind of thing had passed. But I’m very happy with the way it worked out.

What was the interview process like? Did you get any really tough questions?
I got a few questions that I had no idea how to respond to because I don’t have a formal background in engineering. But when the questions played more directly to the research aspect of planetary protection—What are our unknowns? What are the gaps in knowledge?—those were questions I was well-prepared to talk about.

Were you always a science person?
As a child, I would not have used the word “science,” but I couldn’t stand being indoors. My father was always very interested in natural history, so he took me fossil-hunting around the Paleozoic rocks of Southern Minnesota. In high school, I took a lot of science classes up until my senior year, when I decided to stop. In the late ’60s, studying science was not something women did, and I got tired of the constant negativity when I was taking those classes. So I went off to college determined not to pursue science. Then I discovered in the first two years of college that there wasn’t much else I was really good at, so I found my way back.

“We’re in a hurry to get out there, and many of the things humans bring with them are potential contaminants.”

Protecting the planet from alien invasion is a tall order. What does that involve on a day-to-day basis?
I spend a lot of time looking at upcoming space missions that are being planned. So lots of meetings with engineers and scientists.

What are the chances that extraterrestrial life exists?
Depending on who you ask, anywhere between 0 and 99.9 percent. In the past 10 years, the community has tipped toward a sense that it is highly likely we will encounter an extraterrestrial form of life in our solar system, but you’ll find plenty of people who say that’s science fiction. My personal view is that it’s likely we will encounter a lifeform on another planet someday.

If aliens do exist, what might they look like?
It depends on the planet. If there’s life on Mars, it’s probably microbial. And it would have had to evolve in response to a major climate change from the early period in Martian history—3.5 billion years ago, when the planet had water on the surface—to the present-day state of the planet, which is very dry, cold, and windy. So any life on Mars would probably be small and hearty and only sneak out to the surface every 100,000 years when the climate is more mild. If it’s there, it’s tough.

What’s the most important step NASA can take to protect Earth from microscopic threats from other planets?
Now that we’re talking realistically about bringing Martian samples back to Earth, the planning is taking place for what the containment facility will look like and how we get the stuff there. Everyone is working very carefully through that. After the container has landed on Earth—probably some place in Utah—how will those samples be transported to containment? That’s the most important challenge on the horizon right now.

Part of your job is also to protect other planets from us. What’s the biggest threat we pose to the universe?
We’re in a hurry to get out there, and many of the things humans bring with them are potential contaminants. Mars is the first place where that story is likely to play out. There’s a lot of pressure on the scientific community to do a better job assessing the possibility of present-day life on Mars before we arrive with our companion human microbiome and the microbiome associated with plants that we’re going to need to grow for people to eat. It’s a very big challenge to not inadvertently inoculate another habitable world with something from our own planet.

What’s something that has surprised you about the job?
The phenomenal level of effort required to assemble and launch a super-clean spacecraft. I imagined a handful of people. I didn’t think in terms of dozens of people spending 12 to 18 hours a day sampling, cleaning, and monitoring. It’s an impressive human undertaking.

This position required you to move to Washington, D.C., which I’ve heard you weren’t thrilled about. What do you miss most about Indiana?
I miss my husband, the dog, the cat, and Bloomington. I’m not a person who enjoys the noise of life in a cityscape. My husband called me last night to say he had picked a few quarts of cherries from the tree in the front yard, and he was getting them pitted and into the freezer so we could have pies for Thanksgiving. That was hard to hear because I’m not there picking cherries.