U of A Researcher and Alumnus Find Evidence of Briny Water on Mars

Vincent Chevrier
Photo by Russell Cothren

Vincent Chevrier

FAYETTEVILLE, Ark. – Data collected on Mars by NASA’s Curiosity rover and analyzed by University of Arkansas researchers indicate that water, in the form of brine, may exist under certain conditions on the planet’s surface.

The finding, published in the May 2015 issue of the journal Nature Geoscience, is based on almost two years of weather data collected from an impact crater near the planet’s equatorial region. Vincent Chevrier, an assistant professor at the University of Arkansas Center for Space and Planetary Sciences, and Edgard G. Rivera-Valentin, a former Doctoral Academy Fellow at the center who is now a scientist at the Arecibo Observatory in Puerto Rico, were members of the team that analyzed the data as part of a grant from NASA.

“What we demonstrated is that under specific circumstances, for a few hours per day, you can have the right conditions to form liquid brines on the surface of Mars,” Chevrier said.

The existence of briny water may explain a phenomenon observed by Mars orbiters called “recurring slope lineae,” which are dark streaks on slopes that appear and grow during the planet’s warm season.

Water is also necessary for the existence of life as we know it, and on Earth, organisms adapt and thrive in extremely briny conditions. Chevrier, however, believes that conditions on Mars are too harsh to support life.

“If we combine observations with the thermodynamics of brine formation and the current knowledge about terrestrial organisms, is it possible to find a way for organisms to survive in Martian brines? My answer is no,” he said.

Mars is cold, extremely dry, and has 200 times lower atmospheric pressure than Earth. Any pure water on the surface would freeze or boil away in minutes. If it sounds alien for water to both freeze and boil, that’s because it is alien to Earth, but not so much for Mars because of the planet’s very low atmospheric pressure.

However, in 2008, NASA’s Phoenix lander identified perchlorate salts in polar soil samples. Perchlorates are rare on Earth, but they are known to absorb moisture from the atmosphere and lower the freezing temperature of water. The widespread existence of perchlorates makes liquid water possible on Mars.

The Curiosity rover confirmed the existence of perchlorates in equatorial soil, and provided detailed observations of relative humidity and ground temperature in all Martian seasons. With that data in hand, Chevrier and Rivera-Valentin were able to conclude that liquid brines can exist today on Mars. Future Mars missions could sample for the brines directly.

Though the briny water on Mars may not support life, it does have implications for future manned missions that would need to create life-sustaining resources such as water and oxygen on the planet, Chevrier said. There is also the possibility that life once existed on ancient Mars.

“We need to understand the earliest environment,” he added. “What was happening 4 billion years ago?”

About the University of Arkansas: The University of Arkansas provides an internationally competitive education for undergraduate and graduate students in more than 200 academic programs. The university contributes new knowledge, economic development, basic and applied research, and creative activity while also providing service to academic and professional disciplines. The Carnegie Foundation classifies the University of Arkansas among only 2 percent of universities in America that have the highest level of research activity. U.S. News & World Report ranks the University of Arkansas among its top American public research universities. Founded in 1871, the University of Arkansas comprises 10 colleges and schools and maintains a low student-to-faculty ratio that promotes personal attention and close mentoring.

Contacts

Vincent Chevrier, assistant research professor, Center for Space and Planetary Sciences
J. William Fulbright College of Arts and Sciences
479-575-3170, vchevrie@uark.edu

Bob Whitby, features
University Relations
479-575-5709, whitby@uark.edu

Headlines

School of Art Launches Master of Arts in Art History Graduate Program

The art history M.A. degree is an accredited two-year program in partnership with Crystal Bridges Museum and specializes in studying the arts of the Americas.  

Graduate School Awards Outstanding Faculty Mentor, Master's Thesis Awards

Kaleb Turner was honored for his master's thesis, which looked at resilience during the pandemic, and Mike Richardson was honored for their success in mentoring graduate students.

Research Technologist Named Engineering Employee of the Quarter

Jason Crawley, a scientific research technologist with the Department of Computer Science and Computer Engineering, has been selected Employee of the First Quarter for the College of Engineering.

UAPD's SafeZone Mobile App Adds CAPS Services and SEAR Resources to Promote Well-Being

The UAPD's SafeZone Mobile Safety App launched its "Wellbeing" function on Monday, bringing the services and resources of the Counseling and Pschological Services program closer to you.

U of A Speech and Debate Succeeds in Last Tournament of Semester

The students Daisy Rehbock, Luke Hubbard, Megan Dial, Hadley Adkison, Jaci Sabatini, Luke Thurmon, Jacob Hurbanek and Max Green all succeeded in winning at least one round.

News Daily