Zita Martins

Zita Martins
Instituto Superior Técnico

PhD

About

119
Publications
39,902
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2,157
Citations

Publications

Publications (119)
Preprint
We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anoma...
Article
Full-text available
We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXAʼs Hayabusa2 mission. We report the detection of all major presolar grain types with O-and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomal...
Article
Full-text available
Missions to detect extraterrestrial life are being designed to visit Europa and Enceladus in the next decades. The contact between the mission payload and the habitable subsurface of these satellites involves significant risk of forward contamination. The standardization of protocols to decontaminate ice cores from planetary field analogs of icy mo...
Article
Full-text available
With thousands of discovered planets orbiting other stars and new missions that will explore our solar system, the search for life in the universe has entered a new era. However, a reference database to enable our search for life on the surface of icy exoplanets and exomoons by using records from Earth's icy biota is missing. Therefore, we develope...
Article
Current knowledge of the processes that shape prokaryotic community assembly in sea ice across polar ecosystems is scarce. Here, we coupled culture-dependent (bacterial isolation on R2A medium) and culture-independent (high-throughput 16S rRNA gene sequencing) approaches to provide the first comprehensive assessment of prokaryotic communities in th...
Article
Full-text available
With thousands of discovered planets orbiting other stars and new missions that will explore our solar system, the search for life in the universe has entered a new era. However, a reference database to enable our search for life on the surface of icy exoplanets and exomoons by using records from Earth's icy biota is missing. Therefore, we develope...
Article
Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species,...
Article
An interdisciplinary review of the chemical literature that points to a unifying scenario for the origin of life, referred to as the Primordial Multifunctional organic Entity (PriME) scenario, is provided herein. In the PriME scenario it is suggested that the Insoluble Organic Matter (IOM) in carbonaceous chondrites, as well as interplanetary dust...
Article
Executive Summary In this White Paper we propose that NASA works with ESA and other potentially interested international partners to design and fly jointly an ambitious and exciting planetary mission to characterize Europa’s habitability and search for bio-signatures in the environment of Europa (surface, subsurface and exosphere). By choosing the...
Article
Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species,...
Article
Full-text available
Read and share using the Enhanced PDF feature here: https://rdcu.be/b38k6. Analysis of organic matter has been one of the major motivations behind solar system exploration missions. It addresses questions related to the organic inventory of our solar system and its implication for the origin of life on Earth. Sample return missions aim at returni...
Article
Full-text available
Solar system bodies like comets, asteroids, meteorites and dust particles contain organic matter with different abundances, structures and chemical composition. This chapter compares the similarities and differences of the organic composition in these planetary bodies. Furthermore, these links are explored in the context of detecting the most prist...
Article
Full-text available
Carbon-based compounds are widespread throughout the Universe, including abiotic molecules that are the components of the life as we know it. This article reviews the space missions that have aimed to detect organic matter and biosignatures in planetary bodies of our solar system. While to date there was only one life-detection space mission, i.e.,...
Chapter
In the last decades, information regarding the chemistry of the icy moons (those in the outer reaches of the solar system) has been collected and our understanding furthered due to modern telescopes and the success of space missions such as Voyager, Galileo, and Cassini-Huygens. In the present day, there is available data regarding their atmospheri...
Article
Full-text available
The Yilgarn Craton in Australia has a large number of naturally occurring shallow ephemeral lakes underlain by a dendritic system of paleodrainage channels. Processes like evaporation, flooding, erosion, as well as inflow of saline, often acidic and ion-rich groundwater contribute to the (dynamic) nature of the lakes and the composition of the sedi...
Article
Exogenous organic molecules are delivered to the surface of Mars annually, yet their fate is largely unknown. Likewise, the survivability of putative organic biomarkers directly implicates current Mars surface exploration ambitions. Among these, amino acids are valuable target molecules due to their abiogenic and biological origins. We present the...
Poster
Some of the icy moons of Jupiter and Saturn (e.g. Europa, Ganymede and Enceladus) are thought to be habitable environments that may host extra-terrestrial life . Ecosystems analogue to environments on Earth may exist in these icy world . Preparatory work using Earth samples that are analogous to icy moons is critical for the success of future space...
Article
Laboratory experiments that simulate the photo- and thermo-chemistry of extraterrestrial ices always lead to the formation of semi-refractory organic residues. These residues can be considered as laboratory analogs for the primitive organic matter incorporated into comets and asteroids. Many specific organic molecules have been detected in them. He...
Chapter
Astrobiology is one of the new multidisciplinary research fields of the 21st Century requiring collaborations across the physical sciences—astronomers, chemists, geologists, physicists—as well as people from the biosciences and, as discussed in this chapter, the humanities and social sciences. Astrobiology has a along and distinguished history in E...
Article
Full-text available
Carbonaceous chondrites are very primitive meteorites that are rich in carbon. They contain many soluble organic compounds, including nitrogen heterocycles. These play a crucial role in present-day living organisms as they are components of the genetic material and of the co-factors of enzymes. This review outlines the nitrogen heterocycle content...
Conference Paper
On Mars, exogenous organics are delivered to the surface annually, yet their fate is largely unknown. One of the remaining obstacles to assessing Martian habitability is the absence of significant detection of those, and any other organics on the surface, with only trace methane (Webster et al. 2015) and chlorobenzene (Freissinet et al. 2015) tenta...
Article
Full-text available
Scientists use the Earth as a tool for astrobiology by analyzing planetary field analogues (i.e. terrestrial samples and field sites that resemble planetary bodies in our Solar System). In addition, they expose the selected planetary field analogues in simulation chambers to conditions that mimic the ones of planets, moons and Low Earth Orbit (LEO)...
Article
Full-text available
The space environment is regularly used for experiments addressing astrobiology research goals. The specific conditions prevailing in Earth orbit and beyond, notably the radiative environment (photons and energetic particles) and the possibility to conduct long-duration measurements, have been the main motivations for developing experimental concep...
Article
The interaction of 14 different probe organic molecules with the crystalline (010) forsterite Mg2SiO4 surface has been studied at quantum chemical level by means of B3LYP-D2* periodic simulations. The probe molecules are representatives of the class of soluble organic compounds found in carbonaceous meteorites, namely: aliphatic and aromatic hydroc...
Article
Full-text available
Este trabajo es un review interdisciplinar que recoge la historia de 60 años de investigación astrobiológica en el espacio (desde el comienzo de la “Exobiología”, Lederberg 1960), con el fín de obtener respuestas sobre la posibilidad de encontrar vida extraterrestre, los efectos del ambiente espacial sobre microorganismos (ref. protección planetari...
Article
Full-text available
The detection of organic molecules associated with life on Mars is one of the main goals of future life-searching missions such as the ESA-Roscosmos ExoMars and NASA 2020 mission. In this work we studied the preservation of 25 amino acids that were spiked onto the Mars-relevant minerals augite, enstatite, goethite, gypsum, hematite, jarosite, labra...
Article
This work presents an improved analytical procedure for the resolution and quantification of amino acid enantiomers by multidimensional gas chromatography. The procedure contains a derivatization step, by which amino acids were transformed into N(O,S)-ethoxycarbonylheptafluorobutyl esters. It was optimized for the resolution of non-proteinogenic am...
Article
Full-text available
Astrobiology is an interdisciplinary scientific field not only focused on the search of extraterrestrial life, but also on deciphering the key environmental parameters that have enabled the emergence of life on Earth. Understanding these physical and chemical parameters is fundamental knowledge necessary not only for discovering life or signs of li...
Article
Full-text available
The analysis of the organic content of meteorites provides a window into the conditions of the early solar system, such as the extension of aqueous alteration or thermal metamorphism on the meteorite parent bodies. The analysis of the soluble organic content of CM chondrites indicates that extensive aqueous alteration on their meteorite parent body...
Article
Comets, asteroids, meteorites, micrometeorites, interplanetary dust particles (IDPs), and ultra-carbonaceous Antarctic micrometeorites (UCAMMs) may contain carbonaceous material, which was exogenously delivered to the early Earth. Carbonaceous chondrites have an enormous variety of extra-terrestrial compounds, including all the key compounds import...
Article
The Paris meteorite is one of the most primitive carbonaceous chondrites. It is reported to be the least aqueously altered CM chondrite, and to have experienced only weak thermal metamorphism. We have analyzed for the first time the amino acid and hydrocarbon contents of this pristine meteorite by gas chromatography–mass spectrometry (GC–MS). When...
Article
Meteorites are extraterrestrial objects that survive the impact on the Earth's surface. A particular class of meteorites, carbonaceous chondrites, are very old, having remained nearly unaltered since the formation of the solar system approximately 4.6 billion years ago. They contain a rich organic inventory of abiotic molecules with important roles...
Article
Das uns bekannte Leben kontrolliert den ausschließlichen Gebrauch von L-Aminosäure- und D-Zucker-Enantiomeren zum molekularen Aufbau von Proteinen und Nukleinsäuren. In diesem Kurzaufsatz wird aktuellen Modellen zum Symmetriebruch in Biomolekülen nachgegangen, die den Transport erdäußerer präbiotischer Moleküle umfassen. Der Kurzaufsatz stellt Enan...
Article
Life, as it is known to us, uses exclusively L-amino acid and D-sugar enantiomers for the molecular architecture of proteins and nucleic acids. This Minireview explores current models of the original symmetry-breaking influence that led to the exogenic delivery to Earth of prebiotic molecules with a slight enantiomeric excess. We provide a short ov...
Article
The fifth UK Astrobiology Conference (ASB5) - Volume 13 Issue 2 - Charles Cockell, Mark Burchell, Zita Martins
Article
Full-text available
Meteorites can have played a role in the delivery of the building blocks of life to Earth only if organic compounds are able to survive the high pressures and temperatures of an impact event. Although experimental impact studies have reported the survival of organic compounds, there are uncertainties in scaling experimental conditions to those of a...
Article
Full-text available
We analyze here a wide sample of carbonaceous chondrites from historic falls (e.g. Allende, Cold Bokkeveld, Kainsaz, Leoville, Murchison, Murray and Orgueil), and from NASA Antarctic collection in order to get clues on the role of aqueous alteration in promoting the reflectance spectra diversity evidenced in the most primitive chondrite groups. We...
Article
Full-text available
Comets are known to harbour simple ices and the organic precursors of the building blocks of proteins—amino acids—that are essential to life. Indeed, glycine, the simplest amino acid, was recently confirmed to be present on comet 81P/Wild-2 from samples returned by NASA’s Stardust spacecraft. Impacts of icy bodies (such as comets) onto rocky surfac...
Article
Full-text available
The CUC (Close-Up Camera) is part of the selected scientific payload for the MarcoPolo-R mission. It is a powerful, miniaturized, low-power, efficient and highly adaptive system of 820 g, composed of three main parts: a flexible structure focus mechanism allows the acquisition of sharp images of any target from 10 cm to infinity; a colour Active Pi...
Article
Full-text available
The effects of aqueous alteration and thermal metamorphism on the abundance and distribution of meteoritic soluble organic matter were studied on the most primitive CM chondrite, the Paris meteorite.
Conference Paper
The CUC (Close-Up Camera) is part of the selected scientific payload for the MarcoPolo-R mission. It is a powerful, miniaturized, low-power, efficient and highly adaptive system of 820 g, composed of three main parts: a flexible structure focus mechanism allows the acquisition of sharp images of any target from 10 cm to infinity; a colour Active Pi...
Article
Full-text available
Abstract Understanding the processes involved in the evolution of organic matter in the early Solar System requires extensive experimental work. The scientifically valuable carbonaceous chondrites are principal targets for organic analyses, but these meteorites are rare. Meteoritic analog materials available in larger quantities, on which experimen...
Conference Paper
Full-text available
The OREOcube experiment will use in situ spectroscopy to study minerals and organic compounds exposed to LEO radiation conditions on an ISS external platform.
Conference Paper
Three CR chondrites (EET 92159, GRA 95229, and LAP02342) were studied together with the Kaidun microbreccia to get insight into the parent body aqueous alteration.
Article
Full-text available
We conducted field campaigns (EuroGeoMars and ILEWG EuroMoonMars) in the Utah desert to study geology, habitability, and samples in support of Mars-X, MRO, MER, and MSL.
Article
Organic compounds that survive in uncommon space environments are an important astrobiology focus. The ORganics Exposure in Orbit (OREOcube) experiment will investigate, in real time, chemical changes in organic compounds exposed to low Earth orbit radiation conditions on an International Space Station (ISS) external platform. OREOcube is packaged...
Article
Full-text available
Pizzarello et al. (1) recently described the soluble organic content of eight Antarctic Renazzo-type (CR) carbonaceous chondrites and reported large enantiomeric excesses (ee) of l-isoleucine and d-alloisoleucine. The reported values of ee decrease with inferred increases in aqueous alteration. We believe the conclusions presented in the paper are...
Chapter
The genetic code is intrinsic to all living organisms. However, it is still not known what the first replication system was. The origin of the genetic code remains uncertain, and several hypotheses have been proposed. Theories include the synthesis of peptides preceding the appearance of genes (“Metabolic Model”) or molecules of nucleic acids being...
Conference Paper
It is well known that some groups of carbonaceous chondrites (hereafter CCs) accreted with significant organic and water content. We are studying members of rare CC groups from the NASA Antarctic collection in order to get new clues on their astrobiological role. Some of these meteorites are very pristine, and particularly rich in minerals that mak...
Article
The CO3s Colony and Ornans and LL3s Chainpur and Bishunpur were analyzed for the first time for amino acids using gas chromatography-mass spectrometry (GC-MS). Type 3 chondrites have relatively unaltered metamorphic and petrological histories. Chainpur was the most amino acid rich of the four type 3 chondrites with a total amino acid abundance of 3...
Article
We have performed fluorescence spectroscopic analyses of the amino acid content of the Mars soil analog Salten Skov and of an amino acid standard mixture with the same amino acid abundance and distribution as the soil. This is the first study that investigates the total amino acid abundance of a Mars soil analog with a spectrofluorometer and correl...
Article
Efficient detection of organic molecules is fundamental for the success of future life detection missions. Spectrofluorometric analysis is one of the many techniques that may be used to detect organic molecules in extraterrestrial settings. A particularly important class of organic molecules to target is the amino acids on which all terrestrial lif...
Conference Paper
Full-text available
We have performed field campaigns in the Utah desert to study the habitability and biodiversity in relation to geochemical and extreme environmental parameters. The EuroGeoMars2009 and DOMMEX/EuroMoonMars campaigns [1, 2, 9] were conducted at Mars Desert Research station (with the support of NASA Ames, ILEWG, ESA/ESTEC, and partners). The desert ne...
Article
Full-text available
In the present study we have measured the amino acid content of Mars analogue soil samples, and related those results to the microbial and mineralogical data of the soil samples. These were performed on soils collected near the Mars Desert Research Station (MDRS) in the Utah desert (Figure 1), during the EuroGeoMars 2009 campaign [2,3]. The Utah so...
Conference Paper
Full-text available
We have performed field campaigns in the Utah desert to study the habitability and biodiversity in relation to geochemical and extreme environmental parameters. The EuroGeoMars2009 and DOMMEX/EuroMoonMars campaigns [1, 2, 9] were conducted at Mars Desert Research station (with the support of NASA Ames, ILEWG, ESA/ESTEC, and partners). The desert ne...
Article
Future space missions that aim to detect life should search for molecules that are vital to all living organisms. Although the Viking landers did not find any signs of organic molecules on Mars, signatures of past and/or present life may still exist in the Martian regolith. In this paper, we describe amino acid analyses performed in several Martian...
Article
Full-text available
Phyllosilicate minerals and hydrated sulphate minerals have been positively identified on the surface of Mars. Studies conducted on Earth indicate that micro-organisms influence various geochemical and mineralogical transitions for the sulphate and phyllosilicate minerals. These minerals in turn provide key nutrients to micro-organisms and influenc...
Article
Full-text available
We describe the field demonstration of astrobiology instruments and research methods conducted in and from the Mars Desert Research Station (MDRS) in Utah during the EuroGeoMars campaign 2009 coordinated by ILEWG, ESA/ESTEC and NASA Ames, with the contribution of academic partners. We discuss the entire experimental approach from determining the ge...
Article
Several robotic exploration missions will travel to Mars during this decade to investigate habitability and the possible presence of life. Field research at Mars analogue sites such as desert environments can provide important constraints for instrument calibration, landing site strategies and expected life detection targets. We have characterized...
Conference Paper
Full-text available
We have performed field analogue campaigns to study the spatio-temporal variations in habitability signatures by analysing geochemical context and samples.
Article
The early Solar System contained a wide range of abiotic organic compounds. As the Solar System evolved, these organic molecules were incorporated into planetesimals and eventually planetary bodies, such as the parent bodies of meteorites. One particular class of meteorites, the carbonaceous meteorites, contains a large variety of extraterrestrial...
Article
Zita Martins examines some of the challenges involved in the identification and detection of biomarkers.