Martian (Nano)Mineralogy

Summary: The point of this lesson is to introduce students to the basic mineralogy of Martian soils, as well as to x-ray diffraction (XRD) which is a method commonly used to evaluate the atomic structures of natural and synthetic materials. Students will become aware that Martian soils contain significant amounts of iron oxide nanoparticles and consider the importance of these particles in physical characteristics of the planet. They will also consider how the presence of nanosized particles (like those formed during the coagulation step in water treatment) can react with contaminants in soils. The lesson is enhanced by a hands-on activity that uses simulated Martian soil containing a minor amount of ferrihydrite to remove dissolved and particulate contaminants from simulated wastewater.

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Nanoscience Connection: Ferrihydrite is a nanosized mineral found virtually everywhere in Earth surface environments as well as in Martian soils (including Martian soil simulants). It is a critical component in the environment because it controls the transport and fate of contaminants due to its high surface area and reactivity. By learning about Martian soil (nano)mineralogy, students are ready to understand how the reaction of contaminants with nanoparticles in environmental systems e.g., soils is analogous to what happens in the process of conventional water treatment.

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Learning Objectives:

• Describe the general objective(s) of recent Mars rover exploration missions
• Explain what type(s) of information are provided by x-ray diffraction (XRD)
• Describe how Martian soils contain both crystalline minerals and nanosized/amorphous particles
• Explain how ferrihydrite is widespread and important in environmental systems
• Describe a basic column filter experiment

Martian (Nano)Mineralogy

Key Concepts:

• Mars Exploration
• Powder X-ray Diffraction
• Martian Soil Mineralogy
• Column Soil Water Filters

Google images

Module: Environmental Nanoscience

2022 Nanoscience Professional Development Workshop

Credit: NASA

Martian Exploration

Spirit (2004-2010)

Opportunity (2004-2019)

Sojourner�1997

Curiosity�2012-present

https://mars.nasa.gov

Early generations of rovers relied on solar power for mobility, imaging & chemical analysis

Curiosity: A Martian Field Geologist

Radioisotope (11 lbs of plutonium-238) within a graphite shell that goes in electrical generator.

Modern rovers have more powerful and reliable energy sources

https://mars.nasa.gov

Early in its mission, Curiosity’s scientific tools found chemical and mineral evidence of past habitable environments on Mars

https://mars.nasa.gov

Early in its mission, Curiosity’s scientific tools found chemical and mineral evidence of past habitable environments on Mars

Mars

Earth

Moqui Marbles

Mars Landing Sites

https://mars.nasa.gov

Mars Landing Sites

https://mars.nasa.gov

Gale Crater

Curiosity landing area (Aeolis Palus) circled

Spectroscopic evidence of clays and sulfate minerals (initially no direct evidence)

Has a history of water activity…

Physical features such as outflow channels formed by flowing water

CheMin instrument installation into Curiosity

June 15, 2010. �Credit: NASA/JPL-Caltech

Chemistry and Mineralogy (CheMin)

X-ray Diffraction (XRD)

X-ray Fluorescence (XRF)

• An interference phenomenon

Credit: FM Michel

How does diffraction work?

• An interference phenomenon
• Objects with repeating dimensions comparable to the incident wavelength

Credit: FM Michel

How does diffraction work?

Notice how the spacing between grooves is smaller for the DVD (image B)

DOI: 10.1016/j.biomaterials.2013.03.070

• An interference phenomenon
• Objects with repeating dimensions comparable to the incident wavelength

Credit: Google images

Credit: FM Michel

How does diffraction work?

Notice how the spacing between grooves is smaller for the DVD (image B)

DOI: 10.1016/j.biomaterials.2013.03.070

• Pattern contains information about the dimensions and orientations of objects

• Uses X-rays with wavelengths ~0.15 nm
• Comparable to distances between planes of atoms in mineral structures

How does X-ray diffraction work?

0.28 nm

Reminder:

1 nanometer (nm) = 10 Angstroms (Å)

• Uses X-rays with wavelengths ~0.15 nm
• Comparable to distances between planes of atoms in mineral structures
• Patterns provide information on the type of mineral(s) present in powders

Malvern-Panalytical

Credit: FM Michel

How does X-ray diffraction work?

Example diffraction pattern plotted as two-theta angle vs. intensity

Interference pattern image

0.28 nm

• Peak positions and intensities are unique to a mineral’s structure

Unknown

Cristobalite

Stishovite

Quartz

Coesite

XRD “Fingerprinting”

• Peak positions and intensities are unique to a mineral’s structure
• Compare to patterns for known mineral structures

Unknown

Cristobalite

Stishovite

Quartz

Coesite

XRD “Fingerprinting”

• Peak positions and intensities are unique to a mineral’s structure
• Compare to patterns for known mineral structures

Unknown

Cristobalite

Stishovite

Quartz

Coesite

XRD “Fingerprinting”

• Peak positions and intensities are unique to a mineral’s structure
• Compare to patterns for known mineral structures
• Overlapping peaks can be an issue for complex samples

Unknown

Cristobalite

Stishovite

Quartz

Coesite

XRD “Fingerprinting”

Vaniman et al. (2014) Science

Some samples consist of Martian soil – the fine regolith found on the planet surface

Credit: NASA

Rock abrasion tool samples hard rock (pulverizes to powder)

We have learned a lot about Martian mineralogy…

We have learned a lot about Martian mineralogy…

Mars

Mine Drainage

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Mine Drainage

Soils

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Mine Drainage

Soils

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Mine Drainage

Surface Waters

Soils

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Mine Drainage

Surface Waters

Soils

Microbes

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Mine Drainage

Surface Waters

Weathering

Soils

Microbes

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Hot Springs

Mine Drainage

Surface Waters

Weathering

Soils

Microbes

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Mars

Hot Springs

Mine Drainage

Surface Waters

Weathering

Soils

Microbes

Ferritin Core

Ferrihydrite: The most common and important �natural nanoparticle that you have probably never heard of...

Source: Google images

Credit: FM Michel

Column Filter Experiments

FLOW

Credit: www.springer.com (modified)

Hands-On Activity:

• Build a column filter
• Create a simulated wastewater containing dissolved and/or particulate contaminants
• Compare the effectiveness of play sand vs. Martian simulant (containing ferrihydrite) at removing contaminants

Key Takeaways…

• Mars Rovers are revealing new information about the mineralogy of Martian rocks and soils in the search for water and evidence of past life

Key Takeaways…

• Mars Rovers are revealing new information about the mineralogy of Martian rocks and soils in the search for water and evidence of past life
• Ferrihydrite is a highly reactive nanoparticle found virtually everywhere on Earth and in Martian soils (including soil simulants)

Key Takeaways…

• Mars Rovers are revealing new information about the mineralogy of Martian rocks and soils in the search for water and evidence of past life
• Ferrihydrite is a highly reactive nanoparticle found virtually everywhere on Earth and in Martian soils (including soil simulants)
• Simple column experiments demonstrate reactivity of ferrihydrite towards water contaminants