Interdisciplinary investigation of the planet鈥檚 south pole points to clays being the likely culprit

TORONTO, July 29, 2021听鈥�听For years scientists have been debating what might lay under the Martian planet鈥檚 south polar cap after bright radar reflections were discovered and initially attributed to water. But now, a听new听study published in听,听led by planetary scientists from Lassonde School of Engineering at 91亚色, puts that theory to rest and demonstrates for the first time that another material is most likely the answer.

Research led by Isaac Smith, Canada Research Chair and听assistant professor of听Earth听and Space Science at Lassonde听School of Engineering and research scientist at the Planetary Science Institute, uses听multiple lines of evidence to show that听smectites, a common type of clay, can explain all of the observations,听putting the Mars lake theory on ice.

"Since being first reported as bodies of water, the scientific community has shown skepticism about the lake hypothesis and recent publications questioned if it was even possible to have liquid water," said Smith. Papers in 2018 and 2021 demonstrated that the amount of salt and heat听required听to thaw ice at the bottom of the polar cap was much more than Mars provides, and recent evidence showing these radar detections are much more widespread 鈥� to places even harder to thaw ice 鈥� put the idea further into question.

Mars South Polar Layered Deposits on top of Martian Smectites: The multi-kilometer thick south polar ice cap has a base that is composed, at least partially, of a common type of clays. These clays are found over nearly half of the planet's surface and now at the edges of the ice cap. Radar measurements of the clays from a lab led by Smith show that they can explain the bright reflections observed by MARSIS, a simpler explanation than bodies of liquid water.听Credits: ESA/DRL/FU Berlin (top), NASA (bottom).

The research team, which includes researchers from the University of Arizona, Cornell, Purdue and Tulane universities, used听experimental and听modelling听work to demonstrate that听smectites听can better explain the radar observations made听by the听MARSIS听instrument听aboard the European Space Agency鈥檚 Mars Express orbiter. Further, they found spectral evidence that听smectites听are present at the edges of the south polar cap.

鈥淪mectites听are very abundant on Mars, covering about half the planet, especially in the听Southern Hemisphere," said Smith. 鈥淭hat knowledge, along with the radar properties of听smectites听at cryogenic temperatures, points to them being the most likely explanation to the riddle."

Experiments done at 91亚色 measured the radar characteristics of hydrated听smectites听at room temperature and cryogenic temperatures. The radar characteristics in question are two numbers that represent the real and imaginary parts of the dielectric constant. Both numbers are important for fully characterizing a material, but the 2018 study used听modelling听that included only the real part of the dielectric value, leaving out certain classes of materials from being considered 鈥� namely clays.

Spectral color map from the CRISM instrument on Mars Reconnaissance Orbiter draped over HiRISE imagery at the edge of the south polar ice cap. Specific colors from this map indicate the presence of smectite clays, an important discovery that helps to explain the MARSIS radar observations. Credit: NASA/JPL/UA.

Once the experimental measurements were completed, data was evaluated using code. It was in these simulations researchers听found that frozen clays have numbers big enough to make the reflections.

Smectites听are a class of clay that is formed when basalt (the volcanic rock that comprises most of Mars' surface) breaks down chemically in the presence of liquid water.

"Detecting possible clay minerals in and below the south polar ice cap is important because it tells us that the ice includes sediments that have interacted with water sometime in the past, either in the ice cap or before the ice was there,鈥� said Briony Horgan, co-author and associate professor in Earth, Atmospheric, and Planetary Sciences at Purdue University. 鈥淪o, while our work shows that there may not be liquid听water and an associated habitable environment for life under the cap today, it does tell us about water that existed in this area in the past."

To support this new hypothesis,听Smith听conducted听experiments in his听lab听with equipment designed for measuring dielectric values. To simulate the conditions beneath Mars's south polar cap as best as possible, his team froze the clays to -50 C and measured them again, something that had never been done before.听Smith adds that the infrared absorptions attributable to these minerals are present in south polar orbital听visible-near听infrared reflectance spectra. Because these minerals are both present at the听south pole听and can cause the reflections, the team believes this to be a more viable scenario than the presence of liquid water. No salt or heat is听required.

鈥淲e used our听lab听measurements of clay minerals as the input for a radar reflection model and found that the results of the model matched very well with the real, observed data,鈥� said Dan听Lalich,听post-doctoral听researcher at the听Cornell Center for Astrophysics and Planetary Science听at Cornell University and second author on the study. 鈥淲hile it's disappointing that liquid water might not actually be present below the ice today, this is still a cool observation that might help us learn more about conditions on ancient Mars.鈥�

"We analyzed the听MARSIS听radar data and identified observations with high-power values at the base of the south polar layered deposits, both in the proposed lake region and elsewhere," said听Jenny Whitten, co-author and planetary scientist in the听Department of听Earth听and Environmental Sciences at Tulane University.

"The first reason the bright reflectors cannot be water is because some of them continue from underground onto the surface. If that is the case, then we should see springs, which we don't," said Stefano听Nerozzi,听post-doctoral听fellow in the听Lunar and Planetary Laboratory and Department of Geosciences at the University of Arizona and co-author.听"Not only that, but multiple reflectors are stacked on top of each other, and some are even found right in the middle of the polar cap. If this were water, this would be physically impossible."

Putting the results in perspective Smith says the answer is clear.

鈥淣ow, we have the trifecta. One, we measured dielectric properties of materials that are known to exist on over 50 per cent of Mars' surface and found them to have very high values. Two, we听modelled听how those numbers would respond in Mars' south-polar conditions and found them to match the radar observations well. Three, we demonstrated that these minerals are at the听south pole. Because the liquid water theory听required听incredible amounts of heat which is six-to-eight times more than Mars provides, and more salt than Mars has, it was听already听implausible. Now, the clays can explain the observations with absolutely no qualifiers or asterisks.鈥�

About 91亚色

91亚色听is a modern,听multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91亚色's fully bilingual Glendon Campus is home to听Southern Ontario's Centre of Excellence for French Language and Bilingual听Postsecondary听Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning听opportunities听and innovative programs. Together, we can make things right for our communities, our planet, and our future.

About Lassonde School of Engineering

Located in the heart of the multicultural Greater Toronto Area, the听听补迟听91亚色听ishome to engineers, scientists and entrepreneurs, representing a diverse community of students, faculty, staff, alumni and partners. With 11 undergraduate programs, seven graduate programs and a host of certificates and accessible study options, Lassonde is shaping the next generation of creators who will tackle the world鈥檚 biggest challenges and devise creative solutions through interdisciplinary learning opportunities. Lassonde鈥檚 creators think in big systems rather than small silos, design with people in mind and embrace ambiguity.

Media contact:听Kayla Lewis, 91亚色 Media Relations, cell 416-455-4710,听lewiskay@yorku.ca

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OSIRIS-REx mission attempting to get sample from Bennu today: 91亚色 U expert and member of mission science team available to comment

TORONTO, Tuesday, Oct. 20, 2020 鈥撎齌oday, after years of studying the near-Earth asteroid Bennu, the OSIRIS-REx mission will make its first attempt to collect and retrieve a sample from its surface. The mission will use a robotic arm and novel sampling device to collect the sample, more than 200 million miles from Earth, in a Touch-And-Go (TAG) by the NASA spacecraft.

Professor Michael Daly, director of 91亚色鈥檚 Centre for Research in Earth and Space Science (), led the development of the OSIRIS-REx laser altimeter (OLA), which has provided unprecedented topographical measurements of Bennu. This data was instrumental in the selection of a sampling site and navigation of the spacecraft to the surface of Bennu.

A professor in 91亚色鈥檚 Lassonde School of Engineering, Daly is a member of the international team that will receive the Bennu sample on Earth in 2023 for scientific analysis. Through an agreement between NASA and the Canadian Space Agency, Canada will receive four per cent of the pristine sample for future analysis and curation.

Scientists hope the sample will help them to better understand the origins of life and the dynamics of our solar system.

鈥淭he sample is a first for NASA and also for the Canadian Space Agency,鈥� says Daly. 鈥淚t is the culmination of an already successful mission and it will be studied by scientists for decades to come.鈥�

Professor Michael Daly is available for interviews about the role of the laser altimeter data and what he hopes to learn as a member of the team that will be analyzing the sample.

NASA鈥檚 coverage begins at 5pmET. Follow for more info.

听

91亚色 champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91亚色 students and graduates push limits, achieve goals and find solutions to the world鈥檚 most pressing social challenges, empowered by a strong community that opens minds. 91亚色 U is an internationally recognized research university 鈥� our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91亚色 is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni. 91亚色 U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media contact: Anjum Nayyar, 91亚色 Media Relations, cell 437-242-1547,听anayyar@yorku.ca听

The post OSIRIS-REx mission attempting to get sample from Bennu: 91亚色 U expert and member of mission science team available to comment appeared first on News@91亚色.

OSIRIS-REx mission attempting to get sample from Bennu today: 91亚色 U expert and member of mission science team available to comment

TORONTO, Tuesday, Oct. 20, 2020 鈥撎齌oday, after years of studying the near-Earth asteroid Bennu, the OSIRIS-REx mission will make its first attempt to collect and retrieve a sample from its surface. The mission will use a robotic arm and novel sampling device to collect the sample, more than 200 million miles from Earth, in a Touch-And-Go (TAG) by the NASA spacecraft.

Professor Michael Daly, director of 91亚色鈥檚 Centre for Research in Earth and Space Science (), led the development of the OSIRIS-REx laser altimeter (OLA), which has provided unprecedented topographical measurements of Bennu. This data was instrumental in the selection of a sampling site and navigation of the spacecraft to the surface of Bennu.

A professor in 91亚色鈥檚 Lassonde School of Engineering, Daly is a member of the international team that will receive the Bennu sample on Earth in 2023 for scientific analysis. Through an agreement between NASA and the Canadian Space Agency, Canada will receive four per cent of the pristine sample for future analysis and curation.

Scientists hope the sample will help them to better understand the origins of life and the dynamics of our solar system.

鈥淭he sample is a first for NASA and also for the Canadian Space Agency,鈥� says Daly. 鈥淚t is the culmination of an already successful mission and it will be studied by scientists for decades to come.鈥�

Professor Michael Daly is available for interviews about the role of the laser altimeter data and what he hopes to learn as a member of the team that will be analyzing the sample.

NASA鈥檚 coverage begins at 5pmET. Follow for more info.

听

91亚色 champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91亚色 students and graduates push limits, achieve goals and find solutions to the world鈥檚 most pressing social challenges, empowered by a strong community that opens minds. 91亚色 U is an internationally recognized research university 鈥� our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91亚色 is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni. 91亚色 U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media contact: Anjum Nayyar, 91亚色 Media Relations, cell 437-242-1547,听anayyar@yorku.ca听

The post OSIRIS-REx mission attempting to get sample from Bennu: 91亚色 U expert and member of mission science team available to comment appeared first on News@91亚色.

Curiosity Rover鈥檚 measurements hint at subsurface reservoirs of methane on Mars and a strong interaction with surface materials

TORONTO, March 8, 2019听鈥撎鼳 new study led by Professor , an associate professor in the Department of Earth and Space Science and Engineering at 91亚色 has found evidence of a link between the surface rocks and the methane in the atmosphere detected by the Curiosity rover on Mars. Researchers say it is this process that is controlling how much methane is released into the atmosphere above Gale Crater, the landing site of the Curiosity rover.

Previous research has shown that the amount of methane varies from season to season at this location on Mars. There is more methane in the atmosphere when it is warmer and less when it is cooler. However, Moores says until now, there has been no convincing explanation for how the seasonal cycle in methane seen by Curiosity came about. This new research provides a plausible mechanism for producing this effect and calculates how much methane needs to be involved. These results are consistent with other analyses of the behaviour of methane on Mars.

In the study, researchers developed a computer model of the movement of methane through the subsurface and compared how much methane found its way into the atmosphere to the amount measured by the Curiosity Rover鈥檚 SAM-TLS instrument. The team then adjusted the enthalpy of adsorption, a measure of how sticky methane is on regolith (rock in the soil)听until they produced a match.

This allowed his team and collaborators from the University of Colorado, Boulder; the University of Michigan; Universit茅 Paul Sabbatier; NASA-Goddard; Aeolis Research; and NASA-JPL, to estimate the amount of microseepage on Mars at Gale Crater. Gale Crater鈥檚 unique environment makes it easier to detect seeps. However, over most of Mars, the atmospheric mixing is stronger than at Gale Crater, and researchers believe the changes observed in the seasonal cycle will be harder to detect even for the same amount of seepage of methane in most other areas of Mars. NASA鈥檚听听landed in the Gale Crater on Mars in 2012 and was used to provide a snapshot of Mars鈥� surfaces over time.

鈥淭his study shows that the methane seen by the Curiosity Rover likely originates in the subsurface of Mars,鈥� says Moores. 鈥淲e are also able to explain a likely mechanism for producing the seasonal cycle in methane levels that the Curiosity rover has recorded on Mars."

"We expect these processes to operate on Mars because they certainly happen on the Earth, so it鈥檚 not surprising, we were surprised however, by how well everything matched up once we started to change how the soil and the methane interacted with one another.鈥�

This study was produced under the collaboration with the Curiosity Rover Science and Operations team at NASA. J.E.M and C.L.S knowledge funding for the study was provided by the Canadian Space Agency鈥檚 Mars Science Laboratory Participating Scientist Program. The study is published in the most recent issue of .

91亚色 champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91亚色 students and graduates push limits, achieve goals and find solutions to the world鈥檚 most pressing social challenges, empowered by a strong community that opens minds. 91亚色 U is an internationally recognized research university 鈥� our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91亚色 is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni.
91亚色 U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media Contact:听Anjum Nayyar, 91亚色 Media Relations, 416-736-2100 ext. 44543,听anayyar@yorku.ca

The post New research led by 91亚色 U planetary scientist provides clues on methane鈥檚 interaction with surface of Mars appeared first on News@91亚色.