2009 Annual Science Report
Arizona State University Reporting | JUL 2008 – AUG 2009
Habitability of Water-Rich Environments, Task 4: Evaluate the Habitability of Ancient Aqueous Solutions on Mars
We aim to reconstruct the compositions of ancient fluids on Mars by combining computational models with data on the mineralogy of Mars surface materials as they are preserved today. This effort requires that we better understand how well the types of data obtained today and in future missions reflects the mineralogy that exists today. In this task, we have begun to collect such data at Yellowstone National Park, an analog for possible hydrothermal sites on Mars, and have advanced the use of thermodynamic models to interpret observed mineralogical assemblages.
A variety of field and computational studies are underway to improve our ability to reconstruct the compositions of aqueous fluids on past or present Mars from observations of minerals formed from these fluids. These studies were led by Co-Is Jack Farmer and Mikhail Zolotov.
Co-I Farmer and students collected and analyzed samples from siliceous hot springs in Yellowstone National Park in summer, 2009, to assess differences in minor and trace element abundances and accessory mineral compositions of silica sinters, over a broad range of pH and temperature. They utilized the Terra (portable XRD) instrument to characterize sinter mineralogy in the field for future calibration of MSL data. During this expedition they also collaborated with NAI members from NASA Ames (Linda Jahnke and post-doc Niki Parenteau) to study controls of biomarker preservation of siliceous hot spring sinters.
The Yellowstone efforts were also joined by graduate students Chris Edwards and Alice Baldridge from collaborator Phil Christensen’s research group. They characterized the hydrothermal systems using IR (thermal) emission and visible/near-IR spectroscopy, for comparison with data from instruments on MER and current orbiters.
Co-I Zolotov developed a new thermodynamic model to argue for a novel mechanism responsible for deposition of carbonates in the ALH 84001 Martian meteorite. The idea is that low-temperature CO2-rich fluids leached Mg and Fe from rocks followed by CO2 degassing and non-equilibrium sequential deposition of Ca-, Fe-, and Mg-carbonates. This work was collaborative with Paul Niles (NASA JSC) and published in Earth and Planetary Science Letters (Niles et al., 2009).
Co-I Zolotov and collaborators Mikhail Mironenko and Thomas Sharp worked with Amy McAdam (NASA Goddard Center) on thermodynamic modeling of high-temperature deposition of amorphous silica that is detected on Mars.
PROJECT INVESTIGATORS:Jack Farmer
Project InvestigatorMikhail Zolotov
PROJECT MEMBERS:Everett Shock
RELATED OBJECTIVES:Objective 2.1