Carles E. Moyano-Cambero

The key role of meteorites in the formation of relevant prebiotic molecules in a formamide/water environment

We show that carbonaceous chondrite meteorites actively and selectively catalyze the formation of relevant prebiotic molecules from formamide in aqueous media. Specific catalytic behaviours are observed, depending on the origin and composition of the chondrites and on the type of water present in the system (activity: thermal > seawater > pure). We report the one-pot synthesis of all the natural nucleobases, of aminoacids and of eight carboxylic acids (forming, from pyruvic acid to citric acid, a continuous series encompassing a large part of the extant Krebs cycle). These data shape a general prebiotic scenario consisting of carbonaceous meteorites acting as catalysts and of a volcanic-like environment providing heat, thermal waters and formamide. This scenario also applies to the other solar system locations that experienced rich delivery of carbonaceous materials, and whose physical-chemical conditions could have allowed chemical evolution.

UV to far-IR reflectance spectra of carbonaceous chondrites - I. Implications for remote characterization of dark primitive asteroids targeted by sample-return missions

We analyse here a wide sample of carbonaceous chondrites from historic falls (e.g. Allende, Cold Bokkeveld, Kainsaz, Leoville, Murchison, Murray, Orgueil and Tagish Lake) and from NASA Antarctic collection. With the analysis of these meteorites we want to get new clues on the role of aqueous alteration in promoting the reflectance spectra diversity evidenced in the most primitive chondrite groups. The selected meteorite specimens are a sample large enough to exemplify how laboratory reflectance spectra of rare groups of carbonaceous chondrites exhibit distinctive features that can be used to remotely characterize the spectra of primitive asteroids. Our spectra cover the full electromagnetic spectrum from 0.2 to 25µ mb y using two spectrometers. First one is an ultraviolet (UV)–near-infrared (NIR) spectrometer that covers the 0.2–2µm window, while the second one is an attenuated total reflectance infrared spectrometer covering the 2–25µm window. In particular, laboratory analyses in the UV–NIR window allow obtaining absolute reflectance by using standardized measurement procedures. We obtained reflectance spectra of specimens belonging to the CI, CM, CV, CR, CO, CK, CH, R and CB groups of carbonaceous chondrites plus some ungrouped ones, and it allows identifying characteristic features and bands for each class, plus getting clues on the influence of parent body aqueous alteration. These laboratory spectra can be compared with the remote spectra of asteroids, but the effects of terrestrial alteration forming (oxy)hydroxides need to be considered.

Asteroid Mining: Mineral Resources in Undifferentiated Bodies from the Chemical Composition of Carbonaceous Chondrites

Humanity has been mining Earth deposits for decades in order to extract tiny amounts of economically valuable metals and thereby, producing huge natural devastations of our planet. Recently, asteroids have grabbed our attention since they are fascinating objects carrying the hints of Solar System origin and, at the same time, containing large amounts of valuable resources including platinum group metals (Mining the sky: untold riches form the Asteroids, Comets, and Planets, Reading, 1996), iron, nickel, rare earth elements (REE), and water (Mining the sky: untold riches form the Asteroids, Comets, and Planets, Reading, 1996; The technical and economic feasibility of mining the Near Earth Asteroids. PHD thesis, 1997). At present, 14,036 near-Earth objects (NEOs) are known to travel around an orbit close to the Earth, from which 1684 are considered potentially hazardous asteroids (PHAs). In this scenario, may not be surprising that some private companies start considering asteroid mining. In the present study, we report the bulk rare-earth element (REEs, La-Lu) compositions of 38 carbonaceous chondrites as well as 2 R-chondrites, including 5 falls and 35 finds, by using inductively coupled plasma mass spectrometry (ICP-MS) technique. The CI-chondrite-normalized REE patterns show enormous Ce anomalies and large LREE enrichments never described before, attributed to the small sample size and terrestrial contamination. We have also found the characteristic Tm anomalies described by some authors (Acta 163:234–261, 2015; Geochim. Cosmochim. Acta 176:1–17, 2016) attributed to type II CAIs. We conclude that from the point of view of abundances, REEs are not worth mining yet for PGEs may be reasonable. In any case, the current inequality between supply and demand of rare earths is a real problem that will result in large price instabilities for many sectors of the economy, also having negative effects in new technologies and development. Consequently, we envision that space exploration will be a way to find the new resources required to sustain market economy over longer timescales.

Nanoindenting the Chelyabinsk Meteorite to Learn about Impact Deflection Effects in asteroids

The Chelyabinsk meteorite is a highly shocked, low porosity, ordinary chondrite, probably similar to S- or Q-type asteroids. Therefore, nanoindentation experiments on this meteorite allow us to obtain key data to understand the physical properties of near-Earth asteroids. Tests at different length scales provide information about the local mechanical properties of the minerals forming this meteorite: reduced Youngs modulus, hardness, elastic recovery, and fracture toughness. Those tests are also useful to understand the potential to deflect threatening asteroids using a kinetic projectile. We found that the differences in mechanical properties between regions of the meteorite, which increase or reduce the efficiency of impacts, are not a result of compositional differences. A low mean particle size, attributed to repetitive shock, can increase hardness, while low porosity promotes a higher momentum multiplication. Momentum multiplication is the ratio between the change in momentum of a target due to an impact, and the momentum of the projectile, and, therefore higher values imply more efficient impacts. In the Chelyabinsk meteorite, the properties of the light-colored lithology materials facilitate obtaining higher momentum multiplication values, compared to the other regions described for this meteorite. Also, we found a low value of fracture toughness in the shock-melt veins of Chelyabinsk, which would promote the ejection of material after an impact and, therefore, increase the momentum multiplication. These results are relevant considering the growing interest in missions to test asteroid deflection, such as the recent collaboration between the European Space Agency and NASA, known as the Asteroid Impact and Deflection Assessment mission.

Annama H chondrite—Mineralogy, physical properties, cosmic ray exposure, and parent body history

The fall of the Annama meteorite occurred early morning (local time) on April 19, 2014 on the Kola Peninsula (Russia). Based on mineralogy and physical properties, Annama is a typical H chondrite. It has a high Ar-Ar age of 4.4 Ga. Its cosmic ray exposure history is atypical as it is not part of the large group of H chondrites with a prominent 7 - 8 Ma peak in the exposure age histograms. Instead, its exposure age is within uncertainty of a smaller peak at 30 \pm 4 Ma. The results from short-lived radionuclides are compatible with an atmosperic pre-entry radius of 30 - 40 cm. However, based on noble gas and cosmogenic radionuclide data, Annama must have been part of a larger body (radius >65 cm) for a large part of its cosmic ray exposure history. The 10Be concentration indicates a recent (3 - 5 Ma) breakup which may be responsible for the Annama parent body size reduction to 30 - 35 cm pre-entry radius.

Chelyabinsk Meteorite as a Proxy for Studying the Properties of Potentially Hazardous Asteroids and Impact Deflection Strategies

Most asteroids of the near-Earth population have experienced significant collisional processing since they formed, being disrupted and excavated and consequently producing smaller bodies that are delivered from the Main asteroid Belt to the near-Earth asteroid region, thanks to planetary resonances and non-gravitational forces. By studying meteorites arrived to Earth we can obtain clues on this processing through the study of shock metamorphism and brecciation of their rock constituents, among other features. The massive Chelyabinsk meteorite fall produced about one metric ton of meteorites that can be analyzed to decipher the physical processes affecting the surface of this Potentially Hazardous Asteroid. Here we describe physical properties of Chelyabinsk samples, and how impact processing has affected asteroid albedos, a first step in order to relate this data with the reflectance properties of near-Earth asteroids population. This information will be of major interest for future asteroid deflecting missions.

SNC Meteorites: Atmosphere Implantation Ages and the Climatic Evolution of Mars

SNC meteorites are Martian rocks that provide valuable information about the atmospheric composition of Mars over time. These meteorites experienced significant shock during the impact that released them from Mars, and during the flight through the Martian atmosphere some of the gases were retained in the melted shock-altered glasses. As using different radiogenic systems can precisely date such shock processes, SNC achondrites can be considered time capsules capable of providing significant insight into the atmospheric evolution of Mars. Different SNCs were released by impacts at different times, having then different atmosphere-implantation ages, so in practice we can obtain clues on the composition of Mars’ atmosphere at different times. Taking this information into account, we have developed a 1D model of the evolution of Martian Mars’ atmosphere mass, near surface temperature and pressure.

Petrographic and geochemical evidence for multiphase formation of carbonates in the Martian orthopyroxenite Allan Hills 84001

Martian meteorites can provide valuable information about past environmental conditions on Mars. Allan Hills 84001 formed more than 4 Gyr ago, and owing to its age and long exposure to the Martian environment, and this meteorite has features that may record early processes. These features include a highly fractured texture, gases trapped during one or more impact events or during formation of the rock, and spherical Fe-Mg-Ca carbonates. In this study, we have concentrated on providing new insights into the context of these carbonates using a range of techniques to explore whether they record multiple precipitation and shock events.The petrographic features and compositional properties of these carbonates indicate that at least two pulses of Mg- and Fe-rich solutions saturated the rock. Those two generations of carbonates can be distinguished by a very sharp change in compositions, from being rich in Mg and poor in Fe and Mn, to being poor in Mg and rich in Fe and Mn. Between these two generations of carbonate is evidence for fracturing and local corrosion.

A plausible link between the asteroid 21 Lutetia and CH carbonaceous chondrites

A crucial topic in planetology research is establishing links between primitive meteorites and their parent asteroids. In this study we investigate the feasibility of a connection between asteroids similar to 21 Lutetia, encountered by the Rosetta mission in July 2010, and the CH3 carbonaceous chondrite Pecora Escarpment 91467 (PCA 91467). Several spectra of this meteorite were acquired in the ultraviolet to near-infrared (0.3 to 2.2 {\mu}m) and in the mid-infrared to thermal infrared (2.5 to 30.0 {\mu}m or 4000 to ~333 cm^-1), and they are compared here to spectra from the asteroid 21 Lutetia. There are several similarities in absorption bands and overall spectral behavior between this CH3 meteorite and 21 Lutetia. Considering also that the bulk density of Lutetia is similar to that of CH chondrites, we suggest that this asteroid could be similar, or related to, the parent body of these meteorites, if not the parent body itself. However, the apparent surface diversity of Lutetia pointed out in previous studies indicates that it could simultaneously be related to other types of chondrites. Future discovery of additional unweathered CH chondrites could provide deeper insight in the possible connection between this family of metal-rich carbonaceous chondrites and 21 Lutetia or other featureless, possibly hydrated high-albedo asteroids.

Aqueous alteration vs. shock in Villalbeto de la Peña polymict chondritic breccia

Veins of clay and carbonate in the nakhlite meteorite Lafayette formed by dissolution and replacement of olivine.NanoSIMS measurements record δD values up to +4725‰ in Lafayette which reveal martian waters of crustal origin are incorporated into the smectite and adjacent olivine.