Planetary Samples Research Articles

Planetary Paleomagnetic Intensity Recording Fidelity Test Using a Synthetic Lava

AbstractMeteorite paleomagnetism is fundamental to understanding planetary dynamo processes and the evolution of the early Solar System. However, due to the extraterrestrial and ancient origins of meteorites, their paleomagnetic recording fidelity remains uncertain, which can be tested from a planetary sample formed in a known field. On Earth, historic lavas are used to examine paleomagnetic recording fidelity through the Thellier‐series experiment and other paleointensity methods, which can produce paleointensity estimates to test against the known field strength. But natural terrestrial rocks have different magnetic mineralogy from planetary samples, so they cannot faithfully infer the recording fidelity of meteorites. Here, we used an iron‐particle‐bearing sample from the Syracuse University Lava Project (SULP), which is analogous to the lunar basalts and howardite‐eucrite‐diogenite meteorites and forms in the present‐day Earth's field, to investigate the recording fidelity of these meteorites. No remanence has been identified in the high coercivity range with alternating field (AF) demagnetization due to the sample's low coercivity and AF noise, which produces underestimated paleointensities. Two accurate thermal paleointensities indicate that we may acquire accurate paleointensities from non‐ideal multidomain (MD) iron grains with the Thellier‐Coe and RESET methods, but the success rate is low due to the MD effect and thermal alteration in the experiments. Our results imply that MD iron‐bearing meteorites have the potential to provide accurate paleointensities that can be used to constrain planetary processes.

Exploring the internal textures and physical properties of digitate sinter in hot springs: Implications for remote sampling on Mars

Hydrothermal silica deposits on the surface of Mars with textures analogous to terrestrial hot spring deposits are, arguably, one of the best potential targets in the search for evidence of life beyond Earth. Here we investigate terrestrial hot spring digitate silica structures (modern: El Tatio, Chile; Mars Pool at Rotokawa geothermal area, and Te Kopia thermal stream, New Zealand; 1.6–1.8 ka: Opal Mound, Utah, U.S.A.), which are texturally and mineralogically analogous to martian deposits in the Columbia Hills of Gusev crater, in order to elucidate how their physical properties vary with depositional environment, and to help guide future remote sampling endeavors. Micro-computed tomography allows visualization of the internal texture of geological materials through variations in porosity and relative density, and is demonstrated here as a key, non-invasive technique for investigating future returned planetary samples. Bulk porosity, associated with pore sizes greater than >1–2 μm, varies from 4.7 to 21.3% in the four studied terrestrial digitate sinter samples, representing a range of fluid pHs of formation. Moreover, density variations between laminae largely reflect a nano-scale porosity (<1–2 μm) controlled by silicification of microbial material and/or recrystallization due to incipient diagenesis. Nano-indentation measurements of the digitate structures reveal variations in hardness and the reduced Young's modulus. The hardness of opal-A in modern digitate sinter varies, on average, from 2 to 4 GPa (El Tatio, Mars Pool, Te Kopia), but hardens with incipient diagenesis to >6 GPa (Opal Mound). Regions of nano-porous silica in all samples reduces the hardness in these areas to <1 GPa. No significant variation in material properties can be correlated to different fluid chemistries of the modern samples. Collectively, these results imply that the preservation of silicified microbes in digitate sinter structures should lead to a decrease in material hardness and elastic modulus owing to higher porosity in microbial laminae, whereas recrystallization of opal-A or secondary fluid precipitation will lead to hardening. For future remote sampling on Mars, the range of material properties of siliceous materials must be considered when designing appropriate sampling devices, as martian materials both harder and softer than accounted for in the design process may create sampling challenges.

Beyond Two-dimensional Mass–Radius Relationships: A Nonparametric and Probabilistic Framework for Characterizing Planetary Samples in Higher Dimensions

Fundamental to our understanding of planetary bulk compositions is the relationship between their masses and radii, two properties that are often not simultaneously known for most exoplanets. However, while many previous studies have modeled the two-dimensional relationship between planetary mass and radii, this approach largely ignores the dependencies on other properties that may have influenced the formation and evolution of the planets. In this work, we extend the existing nonparametric and probabilistic framework of MRExo to jointly model distributions beyond two dimensions. Our updated framework can now simultaneously model up to four observables, while also incorporating asymmetric measurement uncertainties and upper limits in the data. We showcase the potential of this multidimensional approach to three science cases: (i) a four-dimensional joint fit to planetary mass, radius, insolation, and stellar mass, hinting of changes in planetary bulk density across insolation and stellar mass; (ii) a three-dimensional fit to the California Kepler Survey sample showing how the planet radius valley evolves across different stellar masses; and (iii) a two-dimensional fit to a sample of Class-II protoplanetary disks in Lupus while incorporating the upper limits in dust mass measurements. In addition, we employ bootstrap and Monte Carlo sampling to quantify the impact of the finite sample size as well as measurement uncertainties on the predicted quantities. We update our existing open-source user-friendly MRExo Python package with these changes, which allows users to apply this highly flexible framework to a variety of data sets beyond what we have shown here.

The ESCAPE system: A combined Raman and time-resolved laser-induced fluorescence instrument to analyze planetary material in a controlled environment

Several sample-return missions such as OSIRIS-REx, Hayabusa2, and Mars 2020 recently have or are currently, collecting the most pristine planetary samples we can analyze on Earth since the Apollo missions. Therefore, it is essential to create instrumentation that will allow preliminary compositional analysis of these materials while preventing oxidation, alteration, or contamination from Earth’s environment. At York University, a small, transportable environmental chamber with temperature, pressure, and atmosphere control has been integrated on an optical table with a combined UV (266 nm) and Green (532 nm) Raman, laser-induced fluorescence, and time-resolved laser-induced fluorescence instrument. This system can collect high-resolution 2D spectroscopic maps, long accumulation point analysis and time-resolved fluorescence ‘fingerprinting’. The sample chamber is capable of pressures <10−4 mbar, temperatures <−20 °C, and different atmospheric compositions such nitrogen, argon, or carbon dioxide via gas hookup. The intended use of the system is to detect and identify minerals and organics within sensitive or fragile planetary samples using minimally destructive laser-based techniques, while maintaining specific environmental conditions to preserve and maintain the pristineness of the material being analyzed, such as samples returned from planetary missions.

Effects of dust attachment on the spectral emittance of spacecraft radiators

In recent years, the method used to collect planetary samples has entailed launching a projectile from a spacecraft onto the surface of a planet at touchdown and collecting the sample raised by the impact. However, there is concern that the dust that is raised at touchdown would adhere to the radiator and affect radiative emissions from the radiator into deep space and radiative reflectance against irradiance from the sun and planets into the radiator. In other words, the dust could affect the thermal control of the spacecraft. Using electromagnetic field analysis, a new evaluation parameter was introduced in this study, and the effect of dust particles on the radiation heat transfer of a SiO2 substrate surface, which is commonly used in spacecraft radiators, was calculated. The electromagnetic field analysis was validated experimentally by spectroscopy. The effects of dust particle size, adhesion, and material on the changes in radiative properties were quantified and analyzed. It was suggested that dust particles could change the radiative properties of the radiator and adversely affect thermal control. This effect increased with increasing particle adhesion.

Using the potassium‐argon laser experiment (KArLE) to date ancient, low‐K chondritic meteorites

AbstractSeveral laboratories have been investigating the feasibility of in situ K‐Ar dating for use in future landing planetary missions. One drawback of these laboratory demonstrations is the insufficient analogy of the analyzed analog samples with expected future targets. We present the results obtained using the K‐Ar laser experiment (KArLE) on two old and K‐poor chondritic samples, Pułtusk and Hvittis, as better lunar analogs. The KArLE instrument uses laser ablation to vaporize rock samples and quantifies K content by laser‐induced breakdown spectroscopy (LIBS), Ar by quadrupole mass spectrometry (QMS), and ablated mass by laser profilometry. We performed 64 laser ablations on the chondrites to measure spots with a range of K2O and Ar content and used the data to construct isochrons to determine the chondrite formation age. The KArLE isochron ages on Pułtusk and Hvittis are 5059 ± 892 Ma and 4721 ± 793 Ma, respectively, which is within the uncertainty of published reference ages, and interpreted as the age of their formation. The uncertainty (2σ) on the KArLE ages obtained in this study is better than 20% (18% for Pułtusk and 17% for Hvittis). The precision, which compares our obtained ages to the reference ages, is also better than 20% (11% for Pułtusk and 4% for Hvittis). These results are encouraging for understanding the limits of this technique to measure ancient planetary samples and for guiding future improvements to the instrument.

Concurrent surface enhanced infrared and Raman spectroscopy with single molecule sensitivity.

Surface enhanced infrared absorption (SEIRA) and surface enhanced Raman Spectroscopy (SERS) were simultaneously measured from the same location on plasmonically active substrates. The spectra were acquired using an optical photothermal infrared spectrometer coupled with a Raman spectrometer. The sensitivity of this approach enables exceptionally small quantities of molecules to be interrogated while providing complementary information from both infrared and Raman spectroscopy. This arrangement provides additional improvement of SEIRA through the enhancement of both the optical photothermal detector signal and the infrared absorption. The plasmonic substrates tested were silver nanospheres and a gold coated atomic force microscope tip. The concurrent acquisition of SEIRA and SERS is further demonstrated by nano-sampling material onto an atomic force microscope tip. The analytes, Buckminsterfullerene and 1,2-bis(4-pyridyl) ethylene, were analyzed individually and as mixtures. The concurrent acquisition of SERIA and SERS is a unique approach. It has general applications in trace surface analysis and for the analysis of returned planetary samples.

Validation of the Geant4 PIXE component for incident carbon ions

The goal of this study is to experimentally validate PIXE modelling using the Geant4-ANSTO model (“G4-ANSTO”), distributed for the first time in Geant4 11.0, as well as the Geant4 default model (“G4-default”), for targets bombarded with carbon ions of energies up to 3 MeV/amu, an energy range of importance for PIXE applications.The experimental validation was performed using a variety of target materials, spanning a broad atomic number range. The reference experimental measurements were performed at the ANSTO heavy ion microprobe beamline ANTARES. To the authors’ knowledge, this is the first benchmarking investigation for PIXE simulations in Geant4 utilising carbon ions and it is significant for PIXE-based elemental analysis, encompassing archaeological samples, gas samples, environmental and planetary samples for geological and planetary research studies. It is also of relevance for any physics application, requiring the modelling of particle induced atomic de-excitation or atomic de-excitation only.

Planet Size Controls Fe Isotope Fractionation Between Mantle and Core

AbstractAs an element ubiquitous in the Solar system, the isotopic composition of iron exhibits rich variations in different planetary reservoirs. Such variations reflect the diverse range of differentiation and evolution processes experienced by their parent bodies. A key in deciphering iron isotope variations among planetary samples is to understand how iron isotopes fractionate during core formation. Here we report new Nuclear Resonant Inelastic X‐ray Scattering experiments on silicate glasses of bulk silicate Earth compositions to measure their force constants at high pressures of up to 30 GPa. The force constant results are subsequently used to constrain iron isotope fractionation during core formation on terrestrial planets. Using a model that integrates temperature, pressure, core composition, and redox state of the silicate mantle, we show that core formation might lead to an isotopically light mantle for small planetary bodies but a heavy one for Earth‐sized terrestrial planets.

Development of an electron impact ion source with high ionization efficiency for future planetary missions

Ion sources using electron impact ionization (EI) methods have been widely accepted in mass spectrometry for planetary exploration missions because of their simplicity. Previous space-borne mass spectrometers were primarily designed with the EI method using rhenium tungsten alloy filaments, enabling up to 200 uA emission in typical cases. The emission level is desired to be enhanced because the sensitivity of mass spectrometers is a critical requirement for the future in situ mass spectrometry related to the measurement of trace components in planetary samples. In this study, we developed a new high-emission EI ion source using a Y2O3-coated iridium filament, which has a lower work function than rhenium tungsten alloy. The size of the ion source was 30 mm * 26 mm * 70 mm, and its weight was 70 g. We confirmed that when consuming 3.0 W power, the ion source emits more than 2 mA electrons, which is 10 times greater than the previous models electron emission level. Ionization efficiency of the EI ion source is proportional to the amount of electron emission, which implies our new model increased the ionization efficiency 10 times. We conducted performance tests on the prototype with the 3.0 W heating condition, confirming a high ionization efficiency (10^4 nA/Pa). In addition, we conducted endurance tests of the ion source and demonstrated the persistence of the ionization efficiency for 30 min * 100 cycles.

Dislocation Generation in Experimentally Shocked Olivine Crystals

AbstractDuring shock metamorphism, crystals in planetary bodies are exposed to extreme conditions of stress, pressure, and temperature, resulting in the development of a range of shock‐induced defects, including dislocations. To investigate the shock‐induced development of dislocations in olivine, one of the most common minerals found in meteorites and other planetary samples, a series of shock experiments were carried out on olivine single crystals. Olivine crystals were shocked to peak reverberation pressures ranging from 21.3 to 58.7 GPa in a flat‐plate accelerator. The crystals were characterized using electron backscatter diffraction (EBSD), Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and electron microprobe. EBSD analyses reveal that geometrically necessary dislocations form on all common slip systems. Raman spectroscopy reveals that the full width at half height of characteristic peaks increases linearly as a function of shock pressure. Dislocation loops with the Burgers vector b = [001] have higher densities near fractures as revealed by TEM analyses, whereas dislocations away from fractures are more dependent on the crystal orientation relative to impact direction. The type and density of dislocations that form during shock are largely independent of the starting hydrogen content of crystals. Calculations that incorporate post‐shock cooling rates of meteorites ejected from planetary surfaces, dislocation annihilation rates in olivine, and dislocation densities measured in shocked olivine suggest that shock‐induced dislocations are preserved in olivine in meteorites ejected from planetary bodies and therefore give insight into the conditions of ancient impact events in the solar system.

Determination of strewn fields for meteorite falls

ABSTRACTWhen an object enters the atmosphere it may be detected as a meteor. A bright meteor, called a fireball, may be a sign of a meteorite fall. Instrumentally observed meteorite falls provide unique opportunities to recover and analyse unweathered planetary samples supplemented with the knowledge on the Solar system orbit they had. To recover a meteorite from a fireball event, it is essential that recovery teams can be directed to a well-defined search area. Until recently, simulations showing the realistic mapping of a strewn field were difficult, in particular due to the large number of unknowns not directly retrieved from the fireball observations. These unknowns include the number of fragments and their aerodynamic properties, for which the masses of the fragments need to be assumed in a traditional approach. Here, we describe a new Monte Carlo model, which has already successfully assisted in several meteorite recoveries. The model is the first of its kind as it provides an adequate representation of the processes occurring during the luminous trajectory coupled together with the dark flight. In particular, the model comprises a novel approach to fragmentation modelling that leads to a realistic fragment mass distribution on the ground. We present strewn field simulations for the well-documented Košice and Neuschwanstein meteorite falls, which demonstrate good matches to the observations. We foresee that our model can be used to revise the flux of extra-terrestrial matter onto the Earth, as it provides a possibility of estimating the terminal mass of meteorite fragments reaching the ground.

Oxidation state of iron in fulgurites and Trinitite: Implications for redox changes during abrupt high-temperature and pressure events

Understanding the geochemical effects of shock metamorphism that occur on planetary surfaces is critical when using potentially shocked planetary samples. Fulgurites, formed by lightning strikes on Earth’s surface, could provide an analog for understanding shock metamorphism, because the intense heat and pressure of impact events are similar to those experienced during lightning strikes. The oxidation state generated during impact is the result of temperature (above 2000 K) and pressure (above 10 GPa) conditions, though the composition and physical nature of the country rock are also important. Atomic explosions such as the Trinity nuclear test and the resulting melted surface material Trinitite can also serve as proxies of shock metamorphism. This study compares samples of fulgurite and Trinitite glasses with the associated country rock using petrography, backscattered electron images, and Mössbauer spectroscopy, with a focus on evaluating redox changes associated with lightning-induced and atomic explosion metamorphism as a function of target material. Two fulgurite melts were also subjected to additional analysis using X-ray absorption spectroscopy to assess potential spatial variations in redox state via in-situ microscale measurements. Results indicate lightning-induced redox variations are heterogeneous at micron scales, although the net effect is overall target reduction with an average reduction of Fe3+ by 66%. Moreover, the data show that the physical state of the country rock (i.e., particulate vs. solid rock) has an effect on the magnitude of how the lightning-induced metamorphism effects are observed.

Non-chondritic iron isotope ratios in planetary mantles as a result of core formation

Information about the materials and conditions involved in planetary formation and differentiation in the early Solar System is recorded in iron isotope ratios. Samples from Earth, the Moon, Mars and the asteroid Vesta reveal significant variations in iron isotope ratios, but the sources of these variations remain uncertain. Here we present experiments that demonstrate that under the conditions of planetary core formation expected for the Moon, Mars and Vesta, iron isotopes fractionate between metal and silicate due to the presence of nickel, and enrich the bodies’ mantles in isotopically light iron. However, the effect of nickel diminishes at higher temperatures: under conditions expected for Earth’s core formation, we infer little fractionation of iron isotopes. From our experimental results and existing conceptual models of magma ocean crystallization and mantle partial melting, we find that nickel-induced fractionation can explain iron isotope variability found in planetary samples without invoking nebular or accretionary processes. We suggest that near-chondritic iron isotope ratios of basalts from Mars and Vesta, as well as the most primitive lunar basalts, were achieved by melting of isotopically light mantles, whereas the heavy iron isotope ratios of terrestrial ocean floor basalts are the result of melting of near-chondritic Earth mantle. Planetary materials reveal variation in iron isotope composition across planetary bodies. Experiments suggest that this variation can be explained by varying degrees of fractionation during core formation, depending on temperature.

Formation of the lunar highlands Mg-suite as told by spinel

Two competing hypotheses suggest lunar Mg-suite parental melts formed: (1) by shallow-level partial melting of a hybridized source region (containing ultramafic cumulates, plagioclase-bearing rocks, and KREEP), producing a plagioclase-saturated, MgO-rich melt, or (2) when plagioclase-undersaturated, MgO-rich melts were brought to plagioclase saturation during magma-wallrock interactions within the anorthositic crust. To further constrain the existing models, phase equilibria experiments have been performed on a range of Mg-suite parental melt compositions to investigate which composition can best reproduce two distinct spinel populations found within the Mg-suite troctolites—chromite-bearing (FeCr2O4) troctolites and the more rare pink spinel (MgAl2O4 or Mg-spinel) troctolites (PST). Phase equilibria experiments at 1 atm pressure were conducted under reducing conditions ![Formula][1] and magmatic temperatures (1225–1400 °C) to explore the spinel compositions produced from melts predicted by the models above. Additionally, the experimental data are used to calculate a Sp-Ol, Fe-Mg equilibrium exchange coe to cient to correct natural spinel for sub-solidus re-equilibration with olivine in planetary samples: Sp-Ol ![Formula][2] (R2 = 0.956). Melts from each model (≥50% normative anorthite) produce olivine, plagioclase, and Mg-spinel compositionally consistent with PST samples. However, chromite was not produced in any of the experiments testing current Mg-suite parental melt compositions. The lack of chromite in the experiments indicates that current estimates of Mg-suite parental melts can produce Mg-spinel bearing PST, but not chromite-bearing troctolites and dunites. Instead, model calculations using the MAGPOX equilibrium crystallization program predict chromite production from plagioclase-undersaturated melts (<20% normative anorthite). If so, experimental and model results suggest chromite in Mg-suite crystallized from plagioclase-undersaturated parental melts, whereas Mg-spinel in the PST is an indicator of magma-wallrock interactions within the lunar crust (a mechanism that increases the normative anorthite contents of initially plagioclase-undersaturated Mg-suite parental melts, eventually producing Mg-spinel). The constraints for magmatic chromite crystallization suggest Mg-suite parental melts were initially plagioclase-undersaturated. In turn, a plagioclase-undersaturated Mg-suite parent is consistent with mantle overturn models that predict Mg-suite parent magmas resulted from decompression melting of early ultramafic cumulates produced during the differentiation of a global lunar magma ocean. [1]: /embed/mml-math-1.gif [2]: /embed/mml-math-2.gif

VISTA: A μ-Thermogravimeter for Investigation of Volatile Compounds in Planetary Environments.

This paper presents the VISTA (Volatile In Situ Thermogravimetry Analyser) instrument, conceived to perform planetary in-situ measurements. VISTA can detect and quantify the presence of volatile compounds of astrobiological interest, such as water and organics, in planetary samples. These measurements can be particularly relevant when performed on primitive asteroids or comets, or on targets of potential astrobiological interest such as Mars or Jupiter's satellite Europa. VISTA is based on a micro-thermogravimetry technique, widely used in different environments to study absorption and sublimation processes. The instrument core is a piezoelectric crystal microbalance, whose frequency variations are affected by variations of the mass of the deposited sample, due to chemical processes such as sublimation, condensation or absorption/desorption. The low mass (i.e. 40g), the low volume (less than 10 cm(3)) and the low power (less than 1W) required makes this kind of instrument very suitable for space missions. This paper discusses the planetary applications of VISTA, and shows the calibration operations performed on the breadboard, as well as the performance tests which demonstrate the capability of the breadboard to characterize volatile compounds of planetary interests.

Small melt inclusions can record bulk magma compositions: A planetary example from the Martian basalt (shergottite) Tissint

AbstractMelt inclusions in igneous minerals can provide constraints on magma compositions, especially for planetary samples where mass is severely limited. Small inclusions (&lt;15 μm diameter) are more abundant than large ones, but have been used little from concern that they did not entrap average magma, but are rich in melt of a diffusional layer against the host mineral. We compared bulk compositions and calculated original compositions of small and large melt inclusions in the Martian basalt meteorite (shergottite) Tissint. Small and large melt inclusions are consistent with the same line of igneous differentiation, have the same abundance ratios for incompatible elements (P, Ti, Al, K, Na), and are consistent with derivation from the bulk composition of Tissint (inferred to represent its parent melt composition). For Tissint, then, small melt inclusions show no evidence of entrapping diffusional boundary layers, and appear to have entrapped bulk magma. Thus, its small inclusions can be as useful as larger ones; this may be so for other planetary samples, and thus provides an additional tool for investigating planetary magmas.

The Potassium‐Argon Laser Experiment (KArLE): In Situ Geochronology for Planetary Robotic Missions

Geochronology is a fundamental measurement for planetary samples, providing global and solar system context for the conditions prevailing on the planet at the time of major geological events. The potassium (K)‐Argon (Ar) laser experiment (KArLE) will make in situ noble gas geochronology measurements aboard planetary robotic missions such as rovers and landers. Laser‐induced breakdown spectroscopy (LIBS) is used to measure the K abundance in a sample and to release its noble gases; the evolved Ar is measured by mass spectrometry, and relative K content is related to absolute Ar abundance by sample mass, determined by optical measurement of the ablated volume. This approach allows K and Ar to be measured on identical volumes multiple times to create an isochron, which improves the age determination and reveals irregularities in the rock if they exist. The KArLE technique measures a whole‐rock K‐Ar age with 10% uncertainty or better for rocks 2 Ga or older, sufficient to resolve the absolute age of many planetary samples. The LIBS–mass spectrometry approach is attractive because the analytical components have been flight‐proven, do not require further technical development and provide essential measurements (complete elemental abundance, evolved volatile analysis, micro‐imaging) as well as in situ geochronology.

Effect of Milling Medium on Alumina Additivated with Niobia

Niobia has been successfully used as sintering additive to alumina in order to lower its sintering temperature. This effect can also be obtained by reducing the ceramic particle size. This work investigated the effect of the particle size on the ceramic final density of alumina with 4 wt% niobia. For that two milling media were used. The as-received powders were submitted to ball and planetary milling and then sintered at 1450°C. The planetary milling medium was more efficient in reducing particle size when compared to ball milling. However, planetary milling caused significant contamination in the niobia powder, from the alumina balls used as milling agents. It forced composition balance in order to keep the original proposed formulation. The planetary milled sintered samples showed better densification and lower grain size in comparison with ball milled ones. It could be concluded that the milling medium choice directly affected both microstructure and properties of the sintered alumina with 4wt% of niobia. .

Experimental evidence of fast transport of trace elements in planetary basaltic crusts by high temperature metamorphism

Incompatible elements (IEs) such as K, P, Ti, and rare earth elements (REEs) provide important constraints on the geochemistry and chronology of basaltic meteorites, most of which experienced complicated post-crystallization histories. These elements are immobile under subsolidus conditions because of their slow diffusion rates in planetary basalt minerals such as pyroxene and plagioclase. Thus, IEs are considered to preserve in most cases, reliable records of formation processes, even in ancient rocks that have undergone moderate thermal processing. However, observations of natural planetary samples suggest that melting of IE accessory carrier phases enhances the mobilization of such elements. Here we show that IEs are rapidly transported by near-solidus partial melting of highly IE-enriched minor phases including Ca-phosphate and Ti-rich phases. These partial melts occur as interconnected veins along cracks and fractures, and as thin films on surfaces of pore spaces, indicating that the melt mobilization is driven by surface tension. The melt transport provides the necessary condition for melt migration consistent with the presence of the depleted basaltic eucrites. Also, reaction between major minerals pyroxene and plagioclase, and partial melts may cause disturbance and resetting of some isotopic systems. These results have important implications for a range of geochemical investigations. In particular, the elemental fractionation resulting from such partial melting may result in improper age determinations.