Mars Getaway: Q&A with Earth Sciences Professor Marisa Palucis

by Arianna Khan | 5/1/19 2:15am

Last June, NASA chief scientist Jim Green told USA Today with certainty that humans will be on Mars in the near future. The prospect of starting over on a new planet once we’ve decimated this one is beginning to feel ever-so-slightly less like science fiction than I’m comfortable with. The mere 12 years afforded to the world to stop climate change in its tracks by last year’s UN report can feel a bit like a death sentence. Meanwhile, evidence of historical bodies of water on the now-dry planet of Mars suggests that past life on the planet, at least, is not out of the question.

I spoke with earth sciences professor Marisa Palucis to learn about her research, including exactly how likely we are to send humans to Mars. Palucis’ research aims to understand how fluids shape the Earth, creating landscape features like river channels and deltas. She considers how these processes change with climate and applies her research to Mars as well, investigating when, where and how much water has flowed on its surface.

“I just really like the idea that just by looking at the surface of a planet, you can understand its whole history.”

What’s something you find really interesting or exciting about the work you’re doing?

MP: I think it’s really fascinating that we think that Mars was once much more Earth-like — just thinking about the fact that there’s this planet there today that’s very cold and dry that once had rivers and lakes and maybe an ocean. Just being able to look at a landscape that’s 3 billion years old. Being able to say something about what it looked like and to think of the implications of that, like what if there was life on Mars? And understanding Mars’ past and its current state is also interesting in thinking about sending people to Mars. I just really like the idea that just by looking at the surface of a planet, you can understand its whole history. Its whole history is there — you just have to be able to read it.

What do you think about the possibility of past life on Mars or the prospect of sending humans to Mars in the future?  

MP: A lot of times with the work I do, we’re trying to estimate. Say we have a lake on Mars, and we’re trying to say how long this lake lasted for, and it’ll be 10,000 to a million years. Which sounds like a long time, but life may have needed a much longer period of time. So it seems like you need to have a very long period of time where you have fairly stable conditions for life to develop, and then it’s able to adapt when you have more extreme environments. That’s interesting for me to think about, or at least it puts my work into perspective. It’s really important to think about if there’s an ocean on Mars. Was it there for just a million years, or was it there for the first half billion years, in which case life could’ve evolved on Mars? And then there’s this idea of if it did evolve, as the planet was drying out, did that life go into the subsurface? So, is it still there? And if we go there, we’re going to introduce life, and is that going to somehow affect life there? Even though it’s probably going to be simple life on Mars, we’re going to affect that. I think that’s really interesting. For the scientist part of me, it’s great working with rovers and satellites, but everything’s at a much slower pace because the rovers slowly go along. They can only take pictures from so far, so being able to send actual people there would be amazing. I feel like a geologist could do in a month what it takes years for the rovers to do. I think that aspect of it is really interesting to think about. Maybe someday we’re going to send a person or maybe a group of people to Mars.

Is there a relationship between your work and climate change?

MP: Mars is an example of a planet that has gone through drastic climate change. It once was potentially habitable, and life could have evolved. Due to varying reasons, it’s losing its atmosphere, and now it’s cold and dry. It’s this very drastic example of what can happen when climate change happens. Part of my work is really trying to figure out how that changing climate happened and how it’s recorded in the geology. For the work I do, the work on Earth, I think a lot about these very steep landscapes. A lot of my work has been on the west coast in steep mountain ranges. With climate change there, we’re getting these periods of increased forest fires and wildfire, and the vegetation is really important for keeping soil on the hillslope and not having it transport down into mudslides and into people’s homes. With increased frequency of these fires, and then bigger storms due to climate change, climate change is changing the amount and size and how long fires last and storms last. It’s creating this perfect storm, where you get a lot more risk for landsliding and slope failure and things that really do affect people that either live within those mountain communities or people who live at the base of them. These landslides or debris flows or floods come out of these mountains and essentially onto the floodplain where people live. For me, climate change is not something I think about it in terms of how I can stop it. It’s more just that this is the effect that it’s having on this one aspect of human health and safety. It affects the landscape. And there’s other people within my field who study a more long-term picture. Like if you build up a mountain, that affects the climate pattern and how wind and things move. But for me it’s more how climate is increasing these storms and fires and how that affects landscapes. I’m trying to get a grasp of, before it’s too late, what the baseline is. How do these systems work in general? And this is the hard thing about doing earth science right now. What is the forest fire, climate, debris flow and landslide cycle like? What’s the normal? But we’re in this pattern of change, and so it’s hard to say what’s normal because we’re seeing increased storm sizes, or they’re happening more often or forest fires are hotter or bigger. So it’s hard to get this baseline. That part has been interesting with just trying to figure out if this is normal. Has this been happening for the last hundred years? Is this the new normal?

This interview has been edited and condensed for clarity and length.

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