Discoveries

Below we summarize major research findings and discoveries in Astrobiology that have been made by WARC researchers. In addition to funding from NASA, these projects may have been supported by other funding agencies.

For a complete list of WARC publications, click here.

2018

Understanding paleoclimate conditions from paleosol profiles

Weathering of iron in a reducing planetary environment

Australasian tektite mystery continues

Anoxygenic phototrophs produced 2.75 Ga iron formations

Questioning the Biogenicity of Neoproterozic Superheavy Pyrite by SIMS

Searching for the Great Oxidation Event (GOE) in North America: A reappraisal of the Huronian Supergroup by SIMS sulfur four-isotope analysis

Simultaneous in situ analysis of carbon and nitrogen isotope ratios in the organic matter by secondary ion mass spectrometry

Role of elastic anisotropy in the development of deformation microstructures in zircon

The Rietputs Formation in South Africa: A Pleistocene fluvial archive of meteorite impact unique to the Kaapvaal Craton

New clues from Earth’s most elusive impact crater: Evidence of reidite in Australasian tektites from Thailand

Stable isotope probing of microbial iron reduction in Chocolate Pots hot spring, Yellowstone National Park

Microbial impact on sedimentary carbonate with oscillatory dolomite and limestone layers

Dolomite precipitation induced by sulfate-driven anaerobic oxidation of methane (SD-AOM) in modern methane seeps

Heterogeneous nucleation of calcite on clay minerals

Colloform sphalerite (ZnS) and silver nano-crystals from a modern black smokers

Roles of nano-domains in enhancing magnetic coercivity in lodestones and magnetite

The challenge of obtaining isotopic equilibrium in carbonates

Settling the debate on Earth’s oldest microfossils

Testing the use of oxygen isotopes in quartz to infer ancient ocean temperatures

Geoscience applications of Atom Probe Tomography

One atom at a time: Applying the atom probe to Pb-Pb geochronology

Proving the use of the Atom Probe with geological samples

2017

Analyzing organic molecules and stable isotope ratios of the comet 67P/Churyumov-Gerasimenko

Microbes with a mission – Best practices in sampling and cultivating anaerobic microorganisms for astrobiological studies

Can anaerobic microorganisms survive in Martian conditions?

The highest temperature melt yet recorded – the transformation of zircon to cubic zirconia in meteor impacts

Understanding early protistan biomineralization

Zinc in clay minerals

SIMS standards for Ca-Mg-Fe carbonates.

Perfecting the in situ analysis methods that will be needed for Mars sample return

Iron-oxidizing bacteria flourished in 3 billion-year-old oceans

Space as a Tool for Astrobiology

Don’t have to re-invent the wheel: Natural indices for Lewis acids and bases

New insights into stardust – protoenstatite

Searching for the genes that control extracellular electron transfer

Critical evaluation of the cause of the Ediacaran carbon isotope excursion

Hypervelocity impacts: A P-T diagram for shocked zircons

Microbes eating pyrite

Major review paper on iron formations

Stable potassium isotopes: A new view on weathering

Oldest reported occurrence of anoxygenic phototrophs

Progress report: How possible is it really that life exists elsewhere in the universe?

Addressing the perplexing issue of perchlorates on Mars

Earth as a Tool for Astrobiology

Thrombolites: Understanding carbonate formation in modern microbial mats

Understanding the balance between energy demand and substrate availability for microbial populations at Yellowstone

The source of Martian magnetism? The mineral Luogufengite

The interplay of continental evolution, plate tectonics, and evolution of life

Hardy zircons survive ancient impacts

A hot early Earth shallow ocean

A new approach to dating planetary impacts

Understanding how high-pressure minerals are produced during planetary impacts  

Comparing nanosecond and femtosecond lasers for in situ analysis

Two Billion Years of Magmatism Recorded from a Single Mars Meteorite Ejection Site

A potential new tracer of thermal history using the common mineral feldspar

2016

How to measure super-oxidized materials on Mars

Shocking features in the mineral monazite traces ancient impacts

Extensive continental weathering at 3.2 b.y. ago correlates with the start of modern plate tectonics and early biologic complexity

Ancient microbial iron reduction explains unusual silicon isotope compositions of magnetite-quartz rocks

A new shocked mineral can provide insights into ancient impact events

Techniques crucial to the search for evidence of past life in Mars rocks

Raman spectroscopy documents the effects of Global Climate Change

Raman spectroscopy solves a long-standing problem about fossil preservation

Shocked zircon at Meteor Crater explains formation of granular zircon

Aggregate dust particles at comet 67P/Churyumov–Gerasimenko

A contamination assessment of the CI carbonaceous meteorite Orgueil using a DNA-directed approach

Biological iron and sulfur cycling in Yellowstone

Iron isotope studies of clays indicate unique properties during microbe-clay interactions

Mn-oxide minerals in ferromanganese nodules from Green Bay, Lake Michigan

An ‘‘on-line’’ method for oxygen isotope exchange between gas-phase CO2 and water.

What happens in Mars, doesn’t stay in Mars – a cohesive description of the sedimentation and diagenesis of the Sheepbed Formation

Large Si isotope variations in Archean iron formation record unique Fe bonding

Structural and magnetic properties of nanominerals

Microbes Deciding What is for Dinner

Taxonomy, paleoecology and biostratigraphy of the Lower Cambrian

The origin of sedimentary talc and its relationship to organic matter

What on Earth allowed life to proliferate? 

Carbon isotope evidence for photoautotrophs and chemolithoautotrophs at 3.5 b.y. ago

Breathing with chocolate: iron oxide reduction potential in Chocolate Pots hot spring, Yellowstone National Park

Mineral-eating microbes: genomic analysis of a neutral-pH iron-oxidizing bacterial culture

Fe-oxide minerals in ferromanganese nodules from Green Bay, Lake Michigan

Improved mass spectrometry methods reveal that there is naturally occurring mass-dependent Potassium isotope variations in geological and biological samples

Microbial life mines minerals in a glaciated environment

Isotopic signatures of ancient life and environment at the microbial scale

In situ C isotope measurements of carbonates

In situ O isotope measurements of carbonates

2015

A potential diffusion chronometer based on interdiffusion between ankerite and dolomite 

The geochemical cycle of chlorine and life on Mars

Tracing the food chain to the source of carbon in hydrothermal vent sites, a Europa analog

The role of bacteria in weathering in a glacial environment

Organic compounds on the nucleus of comet 67P/Churyumov-Gerasimenko

Fullerene solves interstellar puzzle

Planetary system formation and the search for life elsewhere in the universe

Using shocked zircons to understand the ages of lunar zircons

The role of organic ligands in forming dolomite

A redox-stratified ocean 3.2 billion years ago requires an earlier evolution of oxygenic photosynthesis

Tracing past microbial communities with isotopes of traces of ancient sea water

Nano- and Micro-geochronology in Hadean and Archean Zircons by Atom-Probe Tomography and SIMS

The significance of microbe-mineral-biomarker interactions in the detection of life on Mars and beyond

Biologically recycled continental iron is a major component in banded iron formations

Who makes which essential components for life in an ecosystem without sunlight?

Ancient shocked minerals identify old impact sites

Bimineralic tubes of oceanic tubeworms, ocean acidification and biofouling

Astrobiology experiments on the International Space Station

Stable magnesium isotopes in carbonates as a tracer of ancient ocean processes

Stable iron isotopes as a tracer of acidic conditions

Evidence for the “null hypothesis” of Darwinian evolution in 2 b.y. old rocks

Life living on basalt lava?

Production of iron sulfides by microbes

The role of biological ligands in catalyzing dolomite formation


2014

Identifying organic molecules in extreme environments

Linking biological and geochemical data in Yellowstone hot springs

The unique biology of hydrothermal systems

The importance of hydrogen metabolisms in early life

Understanding iron-sulfur metalloproteins and the diversity of life

Life under ice: studies of the biology of modern glaciers

Towards a better understanding of diffuse interstellar bands

Low-Earth-orbit radiation exposure studies

A new nanosatellite mission: O/OREOS

Sampling organic-rich asteroids in space: the MarcoPolo-R mission

Simulating space environments for comparison to nanosat missions

How small can you analyze: 4 b.y. old zircons studied by an atom probe

Characterization of microbial communities in low-biomass environments and implications for Mars

The OREOcube (ORganics Exposure in Orbit cube) mission on the International Space Station

The role of laboratory and low-Earth-orbit research in global space exploration

A roadmap for planetary protection

Preparing to visit a comet

Marine serpulid worms calcify far below the carbonate compensation depth

Stable magnesium isotopes may detect the role of biology in weathering

The future of human space exploration and near-Earth targets

The most likely parts of Mars to support life

Understanding pyritization and preservation of organisms in the rock record

Sedimentary dolomite crystals are Ca-rich due to nanophase Ca2Mg(CO3)3

The importance of sulfide to addressing the long-standing problem of producing dolomite in ancient oceans

Advancements in in situ measurements of multiple stable sulfur isotopes

Incorporation of silica in magnetite of banded iron formations


2013

The shapes of layered gypsum deposits can be a biosignature

Tracking the effect on the carbon cycle of microbial communities in a hydrothermal plume from the vent into the water column

Understanding the controls on the oxygen isotope composition of sulfate

Quantifying the oxygen isotope fractionation between, water and sulfite, the key player in the sulfur cycle

Evidence of >4 b.y. weathering on Mars from the ALH84001 meteorite

New methods for in situ analysis: femtosecond laser ablation

Developing international partners is key to future space exploration

The first combined O and Fe isotope study of banded iron formations highlights the need for in situ analysis for understanding these astrobiologically important units

Modern Fe(II)-rich hot springs as an analog to early Earth or Mars

Production of modern banded iron formation in a Swiss lake

Banded iron formation carbonates record microbial processes rather than ancient seawater

Proof of an anoxic ocean 3.5 b.y. ago

Origin of anoxygenic photosynthesis prior to 3.8 b.y. ago

Using nanoparticles to infer ancient environmental conditions

Responsible space exploration

Correlation of δ13C and morphology for organic matter supports biogenicity in in 3.4 Ga Strelley Pool Chert

Analysis of carbon isotope ratios in one-cell microfossils


2012

The importance of developing a global space exploration program

Understanding the delivery of organic compounds to early planets

Silician magnetite – a potential biosignature in BIFs

Iron sulfides in natural environments likely record equilibrium processes as shown by iron isotope fractionations

Iron isotope fractionation between aqueous iron and simulated ancient marine sediments place fundamental constraints on large iron isotope variation in ancient rock record 

A pillar stone in Mg isotope geochemistry

Ancient jaspers may not record early Earth’s atmosphere as previously suggested

Iron isotope fractionation during pyrite formation – how applicable are laboratory experiments to natural systems?

The 2.4 billion-year-old Great Oxidation Event: not a simple step function


2011

Building the next generation of rover-based mass spectrometers

Perfecting ion-microprobe isotopic analysis

Testing the survivability of microbes in space

Silicon and oxygen isotopes for BIF-quartz by SIMS: evidence for continental weathering at 3.8 Ga

Kinetic effects on trace-element substitution in carbonates

The transition into a glacial world 2.4 billion years ago

A step towards deciphering drought histories of Mars using Mg isotopes in sulfate minerals

Astrobiology and habitability studies in preparation for future Mars missions

Analysis of Polycyclic Aromatic Hydrocarbons in Mars Analog Soil Samples

Microbially-mediated iron redox cycling: key roles in modern and ancient sedimentary environments

Direct coupling of microbial extracellular reduction and oxidation of iron

Strontium in dolomite as a potential inorganic biomarker

Understanding how aragonite forms

Stepping Stones Toward Global Space Exploration

Microbially-driven iron isotope fractionation in simulated Archean marine sediments indicate a major role for bacteria in iron formation genesis

Interactions between aqueous iron and poorly crystalline iron hydroxides demonstrate equilibrium atom exchange


2010

Stable iron isotope fractionations in hydrated iron oxides (goethite)

The oldest Martian meteorite is 4.091 billion years old

Shergottite Meteorites are young

Cosmic carbon chemistry

Manganese dendrites are not MnO2, but others

Dissolved hydrogen sulfide can regulate composition of Ca-Mg-carbonate

A new phenomenon for converting mechanical energy into hydrogen energy: implications to tectonic hydrogen production

Ca-Mg-carbonate minerals associated with deep sea methane seeps

A revolutionary new wind-powered rover for Mars exploration

Simulating the first steps of the origin of life in the lab

Cycling of electrons between iron oxides and aqueous iron provides insight into processes on the ancient Earth when oxygen was less

Improving accuracy for in situ oxygen isotope analysis magnetite and hematite – reducing variation due to crystal orientation

High precision in situ measurements of sulfur isotope ratios in sub-15 µm grains by SIMS

Evidence that ~ 2.5 Ga marine BIF carbonates formed through a multi-stage process involving dissimilatory iron reducing bacteria

Evidence for environmental and ecosystem diversity in a 2.7-2.5 billion-year-old sedimentary basin

Magnetite may be an important marker of biological activity

Synergies of Earth science and space exploration

Building long-term constituencies for space exploration: The challenge of raising public awareness and engagement

Discovery of the deepest hydrothermal vents on Earth, an analog for robotic exploration of Jupiter’s icy moon, Europa

Identification of bioorganic molecule-promoted pathway of rapid amorphous solid formation, rather than direct mineral crystal templation, could help determine potential biomineral biosignatures on Mars and other solid worlds

Nitrate-reducing, iron-oxidizing bacteria produce largest iron isotope fractionations yet measured in microbial systems

High precision SIMS stable isotope analyses in minerals – problems and solutions

Study of modern chemically-precipitated sediment confirms probable role of iron-reducing bacteria in generation of isotopically-light iron-bearing minerals in Precambrian banded iron formations


2009

Time and origin of the lunar mantle based on 142Nd/144Nd, 143Nd/144Nd, and 176Hf/177Hf ratios

Habitability in Martian analog environments

Quantifying isotopic diffusion of halide elements, a key to aqueous transport processes

Microbial origin of the oldest stromatolites in the world

Mars analog Río Tinto exposes problems with the classical interpretation of geochemical data

Laboratory experiments show that “iron-eating” bacteria can leave isotope fingerprints under conditions similar to ancient oceans

Carbonate geochemistry may shed light into potential biomarkers on Mars

Novel bacteria discovered in terrestrial alkaline springs that are potential Mars analog sites

What makes a planet habitable?

A new model for the origin of Banded Iron Formations tie ancient surface conditions on Earth to volcanic processes on the early earth

Molecular and physiological analysis of an iron-oxidizing, nitrate-reducing bacterial culture provides insight into chemolithoautotrophic life on Mars


2008

The detection of Extraterrestrial nucleobases in the Murchison meteorite

When did the earth gain its volatile components?

The rain in Spain helps understanding of evaporite sediments on the planet Mars

Searching for minute traces of organic matter on Mars

A possible chlorine isotope biosignature

Differentiating biological and inorganic processes of sulfate formation

Paleohabitability – what was the weather like on Mars in the past?

New insights into planetary soil analogs from laboratory studies

The basis for our genetic code was already in existence 4.5 billion years ago in the solar system

Comet dust reveals unexpected mixing of solar system material

Lithium in the world’s oldest minerals indicate an active weathering cycle in the first few hundred million years of Earth’s history

Isotopic evidence that microbial cycling of carbon, sulfur, and iron developed at different times in the first three billion years of Earth’s history

Evidence that “iron-eating” bacteria existed on the early Earth two to three billion years ago


2007

Amino acid abundances in CR2 chondrites were found to be the highest ever detected in any meteorite

Decomposition of aqueous organic compounds in the Atacama Desert and in Martian soils

An environmental study of acid rain as an analog for ancient Mars

Early histories of the Earth and Moon: Similar, but different

Baked BIFs: Can isotopic biosignatures survive the effects of high-grade metamorphism in the Earth’s earliest sediments?

Preparing for in situ measurements of isotopic biosignatures on Mars

Promising new approaches in micro isotopic analysis of minerals that may record the earliest processes on Earth

The European Space Agency’s ExoMars mission and the search for the organic remnants of life on Mars

A breakthrough in our understanding of the iron isotope fingerprint that iron-eating bacteria may leave in the rock record

Can the iron contents of ancient soils really be used to estimate atmospheric oxygen contents in the early Earth?