My research interests span the solar system — from Mercury to Earth to Jupiter — and my projects have used datasets from laboratories, field sites, Earth-based telescopes, orbital spacecraft and Mars rovers.
Recently my work has focused on unraveling the ancient history of Mars from robotic spacecraft on the planet's surface. Specifically, I want to help answer the question, "were there ever habitable environments on Mars in which life may have developed and thrived?" I am searching for clues about ancient water in the mineral stratigraphy and sedimentary structures on the Martian surface.
As a graduate student, I worked closely with the Mars Exploration Rover (MER) mission, using imaging spectroscopy from the rovers' cameras to study the distribution of minerals that form in warm, wet environments. I also become involved in the landing site selection process for the next Mars rover, Mars Science Laboratory (MSL), studying the history of water at Eberswalde Crater. As a postdoctoral researcher, I am currently working with data MSL's imaging instruments to study the aqueous mineralogy and sedimentology of Gale Crater, Mars. I also use orbital imaging and spectroscopic datasets to help understand the mineral stratigraphy of other key locations on Mars.
Here are some more details on specific research projects:
Understanding the transitions between mineral assemblages in the Mars sedimentary rock record can provide insights into the climatic history of early Mars, and can help us to understand the planet's evolution as a potential environment for early life. Alteration minerals identified in Mars' oldest outcrops (from the Noachian Period, older than ~ 3.7 Ga) are dominated by phyllosilicates with rare occurrences of carbonates, indicating a neutral to alkaline pH alteration environment. Those identified in younger Hesperian (~3.7-3.0 Ga) sedimentary outcrops, however, are dominated by sulfates and occasionally hydrated silica, indicating acidic weathering conditions. The leading hypothesis to explain this global change in mineralogy is that the early, wetter period of alteration ended with the weakening of Mars' magnetic field, which allowed the solar wind to strip the early atmosphere and dry the climate. During this era, volcanoes may have been emitting large quantities of SO2, which acidified available water. Studying the mineral transitions in Martian stratigraphy, therefore, can provide insights into global-scale processes and the climatic history of early Mars.
However, this global alteration model may inadequately account for the possibility of multiple wet environments - and niches for habitability - existing on Mars at the same time. To better understand the environmental transitions during the Noachian and Hesperian eras, my current postdoctoral project is a detailed stratigraphic analysis of key sedimentary rock outcrops on Mars. My detailed mapping work aims to characterize the contacts and cross-cutting relationships of the layers at three of the most significant sedimentary sites on Mars: NE Syrtis Major Planum, Gale Crater, and Juventae Chasma. The rock record at these sites contains key environmental breakpoints, represented by changes in mineral stratigraphy that may have other associated features. For this project I am using imagery from the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) instrument and spectroscopic data from the MRO Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).
Eberswalde Crater, the runner-up landing site for NASA's Mars Science Laboratory (MSL) mission, is famous for the spectacularly preserved delta near its western wall. Using orbital images from the Mars Reconnaissance Orbiter (MRO) HiRISE camera, my collaborators and I have mapped the distribution of other fluvio-deltaic systems in the crater to help assess the potential ancient habitability of the crater. Using key morphologic criteria (e.g. the presence of sinuous landforms that, at lower elevations, terminate at fan-shaped plateaus; meander bends; channel bifurcation initiating basinward of the crater rim), we have identified five smaller systems and mapped their associated sedimentary features. Of particular relevance to habitability and biopreservation is the identification of potential bottomset lacustrine sediments (where organic materials are expected to be concentrated).
We have also studied the structure of Eberswalde Crater as a sedimentary basin. Through identification and mapping of a fault system in and around the crater, we have interpreted the topography of Eberswalde as being largely controlled by dip-slip faulting. Our mapping of the fluvio-deltaic systems within the crater suggests that delta development was controlled by this preexisting topography.
Publications and Conference Abstracts:
M.S. Rice, J.F. Bell III, S. Gupta, N.H. Warner, K. Goddard, R.B. Anderson, A Detailed Geologic Characterization of Eberswalde Crater, Mars, Mars, in press. [download pdf]
M.S. Rice, S. Gupta, J.F. Bell III, N.H. Warner, Influence of Fault-Controlled Topography on Fluvio-Deltaic Sedimentary Systems in Eberswalde Crater, Mars, Geophysical Research Letters, doi:10.1029/2011GL048149, 2011.
S. Gupta, K. Goddard, M.S. Rice, N.H. Warner, J. Kim, J. Muller, Interpreting ancient fluvial and deltaic environments on Mars: what can Earth analogs tell us? American Geophysical Union Fall Meeting, San Francisco, CA, 5-9 December 2011.
M.S. Rice, J.F. Bell III, Assessing the Ancient Habitability of Eberswalde Crater, International Conference on Exploring Mars Habitability, Lisbon, Portugal, 13-15 June 2011.
N.K. McKeown, M.S. Rice, Detailed mineralogy of Eberswalde Crater, Lunar and Planetary Science XXXXII, The Woodlands, TX, 7-11 March 2011.
M.S. Rice, J.F. Bell III, Sedimentary Features within the Proposed Mars Science Laboratory (MSL) Landing Ellipse in Eberswalde Crater, Mars, First International Mars Sedimentology and Stratigraphy Conference, El Paso, TX, 19-21 April 2010.
Our understanding of the surface of Mars has increased exponentially in the past two decades, due to a small fleet of orbiting spacecraft and the Mars Exploration Rovers. Some of the largest discoveries have arguably been made by the spectrometers on all of these spacecraft, which have revealed the distribution of hydrated minerals on the surface and the chemical composition of specific rocks and soils. Spectroscopy will likely play a significant role in the next generation of Mars exploration as well.
My research has focused on using visible to near infrared (Vis-NIR) spectroscopy (400-2500 nm) to understand the nature of water in hydrated minerals and to map their distributions on the surface of Mars, using data collected from the laboratory, from orbit, and from ground-based rovers on Mars. For example, in Vis-NIR spectra from the Mars Exploration Rover (MER) Pancam instruments, the presence of a sharp absorption at ~1000 nm can be used to identify hydrated minerals; my collaborators and I have used this feature to develop a "hydration signature" for the remote identification of potential silica-rich materials and other hydrated minerals. This "hydration mapping" technique can also be applied to observations from the Mars Science Laboratory (MSL) Mastcam instrument.
In my laboratory work, I aim to understand the stability of various hydrated minerals under martian temperature and pressure conditions, which can be critical to the interpretation of spectra from Mars. To characterize the stability of hydrated silica and ferric sulfate minerals on the martian surface, I have studied the spectral changes accompanying the dehydration of laboratory samples over two years in a Mars environment chamber in collaboration with Ed Cloutis at the University of Winnipeg. We have also performed a comprehensive laboratory study of silica at varying water contents, temperatures, pressures and grain sizes, to aid spectroscopic interpretations of silica deposits on Mars.
Publications and Conference Abstracts:
M.S. Rice, E.A. Cloutis, J.F. Bell III, S.A. Mertzman, D.L. Bish, M. Craig, B. Mountain, R.W. Renaut, B. Gautason, Reflectance Spectra Diversity of Silica-Rich Materials: Sensitivity to Environment and Implications for Detections on Mars, Icarus, doi:10.1016/j.icarus.2012.09.021, 2012.
S.W. Squyres, R.E. Arvidson, J.F. Bell III, F. Calef III, B.C. Clark, B.A. Cohen, L.A. Crumpler, P.A. de Souza Jr., W.H. Farrand, R. Gellert, J. Grant, K. E. Herkenhoff, J. A. Hurowitz, J. R. Johnson, B. L. Jolliff, A.H. Knoll, R. Li, S. M. McLennan, D.W. Ming, D.W. Mittlefehldt, T.J. Parker, G. Paulsen, M.S. Rice, S.W. Ruff, C. Schröder, A.S. Yen, K. Zacny, Ancient Impact and Aqueous Processes at Endeavour Crater, Mars, Science, doi:10.1126/science.1220476, 2012.
J.F. Bell III, M.C. Malin, M.A. Caplinger, M.A. Ravine, A.S. Godber, M.C. Jungers, M.S. Rice, R.B. Anderson, Mastcam Multispectral Imaging on the Mars Science Laboratory Rover: Wavelength Coverage and Imaging Strategies at the Gale Crater Field Site, Lunar and Planetary Science XXXXIII, The Woodlands, TX, 19-23 March 2012.
M.S. Rice, J.F. Bell III, Mapping Hydrated Materials with MER Pancam and MSL Mastcam: Results from Gusev Crater and Meridiani Planum, and Plans for Gale Crater, American Geophysical Union Fall Meeting, San Francisco, CA, 5-9 December 2011.
M.S. Rice, J.F. Bell III, E.A. Cloutis, A. Wang, S. Ruff, M. Craig, D. Bailey, J.R. Johnson, P. de Souza Jr., W.H. Farrand, Silica-Rich Deposits and Hydrated Minerals at Gusev Crater, Mars: Vis-NIR Spectral Characterization and Regional Mapping, Icarus, doi:10.1016/j.icarus.2009.03.035, 2010.
M.S. Rice , E.A. Cloutis, J. Crowley, Spectral Reflectance Changes Accompanying Long Duration Exposure of Silica Sinter and Fe-Sulfate Minerals to Mars Surface Conditions, Lunar and Planetary Science XXXXI, The Woodlands, TX, 1-5 March 2010.
E.A. Cloutis, M.S. Rice, J.F. Bell III, S.A. Mertzman, D.L. Bish, R. Renaut, Spectral Reflectance Diversity of Silica-Rich Materials: Insights into Structure and Petrogenesis and Implications for Mars, Workshop on Modeling Martian Hydrous Environments, Houston, TX, 1-3 June 2009.
J.R. Johnson, J.F. Bell III, E. A. Cloutis, M. Staid, W. Farrand, M.S. Rice, A. Wang, A. Yen, Mineralogic Constraints on Sulfur-Rich Soils from Pancam Spectra at Gusev Crater, Mars, Earth and Planetary Science Letters, 2007.
Many of the most important discoveries from the Mars Exploration Rover (MER) Spirit mission were made in the vicinity of Home Plate in the Columbia Hills of Gusev Crater, Mars. Home Plate is a plateau of layered rock interpreted as a pyroclastic flow, and the presence of nearby silica- and sulfate-rich soils, vesicular basalts, and vent-like structures provides further evidence for magma-water interactions at this site. I have studied the visible to near-infrared (Vis-NIR) spectra of the soils near Home Plate using data from Spirit's Panoramic Camera (Pancam) instrument and have found that their mineralogies are consistent with precipitation from hydrothermal fluids. To understand the regional extent of hydrovolcanism, and its potential relationship to the nearby volcano Apolinaris Patera, I advised a summer student on a geomorphologic survey of candidate vents, rootless cones, and "Home Plate like" features in multiple spacecraft datasets from Mars. Ongoing work includes a survey of hydrated minerals using orbital spectroscopy data.
Publications and Conference Abstracts:
M.S. Rice, A. Batista, J.F. Bell III, W.A. Watters, Searching for "Home Plates" Near Gusev Crater, Mars: Spirit's Regional Context in an Area of Explosive Volcanism, American Geophysical Union Fall Meeting, San Francisco, CA, 13-17 December 2010.
A. Batista, M.S. Rice, W.A. Watters, J.F. Bell III, The Distribution of Possible Hydrovolcanic Features in the Vicinity of Gusev Crater, Mars, 42nd Annual Division of Planetary Sciences Meeting, Pasadena, CA, 3-8 October 2010.