Dr. Penny Morrill’s latest research project may help detect life on other planets.
The associate professor of earth sciences in the Faculty of Science recently received a grant from the Canadian Space Agency, through its Flights and Fieldwork for the Advancement of Science and Technology (FAST) funding initiative, for a project titled the Study of Electrical Potential, Remote Sensing and Preservation of Biosignatures at Sites of Serpentinization, or SERP.
“It’s really exciting,” she said.
“We won’t get to look for signs of life on other planets ourselves, but we’re contributing to the research leading to someone else being able to do that.”
The project is broad in scope and includes a number of partners.
Dr. Morrill is the principal investigator and is joined by Dr. Alison Leitch, Department of Earth Sciences; Dr. Kris Poduska, Department of Physics and Physical Oceanography; Dr. Todd Ventura, St. Mary’s University, Halifax; Jerry English, C-CORE; Pauline Honarvar, Geological Survey, Government of Newfoundland and Labrador; Dr. Mark Wilson, a retired Earth Sciences faculty member and co-owner of Spatial Data Management, a geographic information system company; and Nick White and Chris LeGrow from Cloudbreaker, a local drone company.
Serpentinization is a reaction that occurs when groundwater flows through ultramafic rock. It reacts with the rock, creating texture similar to that of the skin of a snake, as well as a unique water chemistry with very high pH values of between 11 and 12. This extreme environment is very inhospitable to most forms of life.
Most, but not all.
“These sites do have quite a bit of life somehow surviving under these conditions,” said Dr. Morrill. “There is also evidence that if serpentinization is not happening currently on Mars, it most likely has happened in the past.
“So, if these sites can harbour life on Earth, perhaps they may have also been able to support life on Mars, or on Saturn’s moon, Enceladus, where we also have reason to believe serpentinization has occurred.”
Since serpentinization happens in the subsurface of the rock, it makes it difficult to find sites to study where it occurs.
“The groundwater will eventually discharge up to the surface in a groundwater spring, and when we can find one, they become our window into the subsurface, but the real challenge is finding those springs,” said Dr. Morrill.
Identifying new sites
Dr. Morrill and her graduate students spend time in the summers hiking up and down valleys in Gros Morne looking for new sites. However, because of the risk of not finding anything, they usually spend most of their time studying known springs.
The goal of the SERP project is to develop remote sensing and subsurface methods to help identify more of these sites.
“C-CORE will look at imagery of a known site, such as Winterhouse Brook Canyon in the Tablelands, to develop methods for finding springs using a satellite,” she said. “Then Cloudbreaker will do the same using a drone at the training site.”
She notes there are plenty of signs for them to look for.
“Very few plants can survive in this extreme environment,” she said. “So, we are looking for the absence of plant life. Also, where these waters discharge onto the surface we’ll see carbonate precipitating, which is basically whiteish rock surrounded by orange rock. While the satellite can look at the vegetation, a drone can look closer for colour differences in the rocks.”
Visual cues aren’t always enough, however.
Dr. Poduska will test the ability of near-infrared spectroscopy to detect the specific types of minerals found in the rocks around these springs. If it works, satellites and drones can both be used to collect this infrared data.
“Satellite data will tell us that maybe something is here,” said Dr. Morrill. “Then we can take the drone in and see if the satellite was right. Finally we can ground truth the drone information by going into the field and looking around for ourselves.”
The team won’t just be looking at spring sites from above. Dr. Leitch’s role is developing methods for imaging the subsurface using magnetic and electrical methods.
Serpentinization can produce the mineral “magnetite,” and she has shown the subsurface fluid pathways of two known springs show up clearly in magnetic surveys.
“Serpentinization reactions, like chemical reactions in a battery, also produce voltage differences,” said Dr. Leitch. “We are planning electrical surveys across the ground surface to see what we can learn about subsurface flow from the voltage differences.”
Signs of life
The first year of the project will be spent at the training site, developing methods. In the second year, the team will apply those methods to a site they’ve never investigated but are fairly certain contains a spring.
Once found, Dr. Morrill’s graduate student, Melissa Cook, in collaboration with Dr. Ventura, will study the signs of life at the springs to see how they are preserved.
“Our goal is to find springs and then figure out if life is there or not,” she said. “Ultimately, we hope to publish the work and it will be accessible to other people, specifically anyone looking at satellite data of other planets.”