Q&A: Cosmic CSI and Looking for Extra-terrestrial Life

4/1/2024 William Gillespie

Written by William Gillespie


Cosmic CSI and Looking for Extra-terrestrial Life

As an astrobiologist employed by the Lunar and Planetary Institute, alumna Kennda Lynch is using her engineering expertise to search for traces of extra-terrestrial life in the solar system and beyond. She talks about the work she is doing with the Perseverance Mars rover, and the possibilities of undiscovered microbial life from the clouds of Venus to the oceans of Europa.

Interviewed by William Gillespie

Dr. Kennda Lynch is an astrobiologist and geomicrobiologist studying life in extreme environments on Earth at the Lunar and Planetary Institute. After obtaining a split bachelors degree in Grainger Engineering’s Industrial and Enterprise Systems Engineering (ISE) department as well as The College of Liberal Arts and Sciences’ Biology department, she worked as a systems engineer for the International Space Station Program and as a research engineer for the Astromaterials and Exploration Science directorate, both at NASA Johnson Space Center. Lynch was one of 100 women profiled in the book "Women of Space: Cool Careers on the Final Frontier" and was featured in the 2018 Netflix series "Explained" (S1, E12) and Nova (S48, E2). In this Q&A, she talks about combining her engineering and science training to work across multiple disciplines within the astrobiology community.

Lynch showed an interest in space from an early age, and while an undergrad at ISE, persuaded Professor Henrique Reis to sponsor the “Floa’tn Illini”—a student group who conducted zero-g experiments aboard a NASA plane. The customizable Systems Engineering and Design degree, with its emphasis on problem solving across disciplines, allowed her to build her career in a very unique way. Now, as an astrobiologist, she studies the possibility of life—especially microbial—outside of Earth’s biosphere. Currently Lynch is working with NASA’s Perseverance Mars rover to look for biosignatures of present or past microscopic life on Mars. Her analog for the Jezero crater on Mars is the Great Basin Paleolakes area of Utah, which hosts hardy microorganisms able to survive in desert conditions that leave telltale biosignatures.

Are there researchers in the astrobiology field looking outside of Goldilocks zones (a habitable zone) for non-CHNOPS-based forms of life?

Oh, absolutely. Even here in our solar system, where Earth is in the Goldilocks zone, we are looking for life in areas technically outside of the traditional Goldilocks zone. We're looking for life on Mars, or in some of our ocean worlds, a lot of which are located on moons of other planets in our solar system. For example, Enceladus, Europa and Ganymede are all moons around Saturn and Jupiter. These are definitely not in the Goldilocks zone, yet we have liquid water persisting in global subsurface oceans in these bodies. And then we have Titan, which, in addition to having a global subsurface ocean, also has liquid methane on its surface, and it's outside the Goldilocks zone. And we're looking at that as a place to look for potential origins of life. Some folks are even looking at whether we can have life processes in the clouds of Venus, not necessarily on the surface where it's too hot and the pressure is too high. So, in our own solar system, we've started to look outside that traditional Goldilocks zone to assess habitability and try to think agnostically, looking for life. We only have one data point, which is Earth.

But we can't look only for the way that life started on Earth, because life on other planets may not have organized itself in the exact same way, or it may not have the exact same set of amino acids, or not built its information structure exactly the same as our DNA and RNA polymer. So yeah, we have a lot of thoughts outside the Goldilocks zone. But, when we're looking for extrasolar planets, it helps us to look at the Goldilocks zone, because that helps us kind of hone in on our targets and gives us something to shoot for. It's a good starting point to kind of look at and you go from there.

Has astrobiology ruled out non-water-based life? Or is it more a question of starting with what we know?

I don't think we've ruled it out. It's more of a question of starting what we know. That's why Titan is going to be so important, because we have these methane lakes, organic sand dunes and a global subsurface briny ocean. This could be a completely weird, different habitat that might be an analog for the origin and evolution of life.

Kennda holding rocks
Kennda in the Great Basin Paleolakes area of Utah.

Is there a definition of what constitutes a life form?

Well, we do have eight general characteristic functions that we all generally agree that are life. Life needs some kind of solvent, such as water, to do chemistry. It also needs some kind of containment system and an information system to store and transfer information to allow it to reproduce itself. Life uses energy from its environment. It extracts that energy from its environment and it releases waste products. And then life evolves and changes and adapts. CHNOPS is a need (or SPONCH) [both are acronyms for carbon, hydrogen, nitrogen, oxygen, phosphorus, and hydrogen, all considered essential for life].

So that's the beautiful thing about astrobiology. [Proving the existence of life] is like the ultimate episode of CSI. You're putting together the biggest forensic case of your life to prove who the killer is, and you’ve got to be able to go to the jury and prove beyond reasonable doubt that you know who's done it.

— Kennda Lynch

And that's kind of what we have to do. We have to do lots and lots of different mutually confirming tests. We think about the common functions of life across the planet, no matter what kind of life it is, and ask what kind of instrument suite would be most useful to us, and what kind of tests and instruments we'd want to put together to go and do a life detection mission.

Tell us about your work in the Jezero crater (on Mars), where the rover Perseverance, AKA “Percy,” is collecting samples.

This is the first time that we're collecting samples from Mars that we hope will get returned to Earth. Yes, Percy is collecting samples that we hope will get sent home within the Mars Sample Return (MSR) architecture.

Do any of the Mars rovers, including Percy, have any diagnostic tools that can help you besides cameras?

Each rover has a science suite. And even the cameras are more than just cameras – they're actually analytical lasers. Percy has a very interesting science suite. It has two cameras that can both do not only imaging, but can also get data about the mineralogy of the rocks through visible near-infrared spectroscopy. SuperCam also has Laser Induced Breakdown Spectroscopy (LIBS) so it can get elemental information from this laser. We can get a lot of information about mineralogy, rock, elemental rock chemistry, chemical abundances and stuff like that, without even touching the rocks—just looking at them and shooting lasers at them.

And then we have an arm on Percy that can collect samples, process them and send samples to other instruments on Percy. We have SHERLOC [Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals] and PIXL [Planetary Instrument for X-ray Lithochemistry], and those are our two big instruments on Percy. SHERLOC is a deep UV Raman system that can look in-depth at the mineralogy and the elemental abundances, and specifically can look at and characterize certain types of groups of organics as well. PIXL can map, so not only can it give us information about elemental abundance, it can actually map and show us in a grid area the different elements that are present. This is actually really powerful information we use to get an idea of what kind of processes are going on based on the elemental mapping.

We also have a weather suite that is giving us a lot of information about atmosphere regolith interactions, and what's going on in the local weather system that will help us understand the climate of Mars now, not just for humans, but understanding the day-to-day processes on Mars.

Kennda and colleague inspecting soil materials
Kennda and colleague inspecting soil.

You likened astrobiology to cosmic CSI. I know that Perseverance was carefully scrubbed with isopropyl alcohol, with extra care given to the sample tubes. But is there risk of rovers “contaminating the crime scene” by bringing microbes from Earth?

Percy was scrubbed to get to a minimal contamination risk. With respect to what we sent on Percy or any other rover before that, NASA has rules for planetary protection that we agree with, and that we try to work with internationally in cooperation with other space agencies. The goal is to protect special regions we think are more likely to have possible preservation of life, or maybe even extant life going—such as places with transient liquid water or ice.

Are there laws for protecting the ecology of Mars? And is the private exploration of Mars bound by these laws?

It's going to be a global diplomatic discussion on how we safely and cleanly explore the Moon and Mars. We're already dealing with unintended consequences of lack of regulations. Astrobotic Technology’s Peregrine lander had human remains on it that people paid for, to have a part of their loved ones interned on the moon. And it really upset the Navajo Nation and Native American populations that revere the moon and really did not want human remains going to the moon. [After the interview, Peregrine had a critical failure and the payload containing the remains of multiple "Star Trek" cast members and the DNA of former U.S. presidents burned up over the South Pacific.]

We're starting to deal with some of these cultural issues and social issues around space. So we have to figure out how to work together.

Are there new technology, telescopes, or probes due to come online that can help you in your search for life?

There's a lot of cool technology that I'm looking forward to! NASA is investing in a lot of different things, not only for Mars but for ocean worlds. So there's a lot of cool instrument suites that are developing ways to do different analyses and detection of different biosignatures—lipids, organic constructions, isotopes, biopolymers, things like that.

Beyond the Great Basin paleolakes of Utah, are there areas on Earth or earthy extremophiles that might serve as analogs for Martian life?

Oh, there's so many. A lot of my colleagues work in the deep subsurface. They work in gold mines and other mines a mile underground, and we learned that there's an amazing dark biosphere that's living there. People that do drilling into the deep ocean crust are finding interesting, amazing life living there. And so we have so many beautiful analog environments, even if we don’t have exactly the same temperature or gravity.

You have stated that you believe that life will be found in our backyard, though maybe not in our lifetime. How can you be so sure?

I find it hard to believe that we are truly a singularity. Given the vastness of our universe, and given the amazing diversity of planet formation, stellar formation, galaxy formation, I find it hard to believe we’re just a blip. It's a belief based on logic and reasoning.

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This story was published April 1, 2024.