arXiv subjects

J. M. Trigo-Rodríguez

Publications and source records attributed to J. M. Trigo-Rodríguez.

3 recordsLinked to original sources

arXiv2025

On the spatiotemporal coincidence of meteorites in recent fall search campaigns

The meteoritical community widely assumes that the probability of finding two meteorites from different falls laying in close proximity is negligible. However, recent studies have suggested that spatiotemporal coincidences may be critical when associating a meteorite with a witnessed fall. In this work, we estimate the number of accumulated meteorites--those resulting from past falls--that are present in landing regions of new falls, while accounting for the effects of terrestrial weathering. We present a simple, fast-computing model to estimate such probability, validated with a Monte Carlo approach based on dark flight computations from real meteorite-dropping fireball data. Considering meteorite masses higher than 10 g, our results indicate that in regions with minimal weathering, like Antarctica, the probability of encountering a previous meteorite within a new fall strewn field may be as high as 75%. In environments with higher weathering rates, like countryside or urban regions, this probability decreases to <1%. When considering the 30 g Lake Frome 006 meteorite coincidence case, the probability of recovering a non-related meteorite with an age of 3.2 kyr from a 0.7 km^2 search area is 6.9%. In the case of the 1 kg Ischgl meteorite, the probability of coincidence with another fresh meteorite of similar mass is 0.06% assuming a large strewn field of 210 km^2. Applied to the Almahata Sitta case, our model predicts a 11.3% of coincidence with a previous meteorite fall. Our results strongly suggest that isotopic dating is essential before associating any meteorite with a witnessed fall.

astro-ph.EP↗

arXiv2025

Mechanical softening and enhanced elasticity of lunar olivine probed via nanoindentation and high-pressure X-ray diffraction measurements

The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions. Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine, (Mg, Fe)2SiO4, in meteorite NWA 12008, a lunar basalt. Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts. Also, we have performed synchrotron-based high-pressure X-ray diffraction (HP-XRD) measurements to probe the compressibility properties of this meteorite and, for comparison purposes, of three ordinary chondrites. The HP-XRD results suggest that the axial compressibility of the orthorhombic $b$ lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite. The origin of the observed differences is discussed. A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects, both of which are necessary to reproduce the observed elastic modulus softening. Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.

astro-ph.EP↗

arXiv2022

Orbital characterization of superbolides observed from space: dynamical association with near-Earth objects, meteoroid streams and identification of hyperbolic meteoroids

There is an unceasing incoming flux of extraterrestrial materials reaching the Earth's atmosphere. Some of these objects produce luminous columns when they ablate during the hypersonic encounter with air molecules. A few fireballs occur each year bright enough to be detected from space. The source of these events is still a matter of debate, but it is generally accepted that they are of sporadic origin. We studied the NASA-JPL Center for NEOs Studies (CNEOS) fireball database to infer the dynamic origin of large bolides produced by meter-sized projectiles that impacted our planet. These likely meteorite-dropping events were recorded by the US Government satellite sensors. We estimated the false-positive rate and analyzed the time evolution of multiple orbit dissimilarity criteria concerning potential associations with near-Earth objects and meteoroid streams. We found that at least 16% of the large bolides could be associated with meteoroid streams, about 4% are likely associated with near-Earth asteroids, and 4% may be linked to near-Earth comets. This implies that a significant fraction of meter-sized impactors producing large bolides may have an asteroidal or cometary origin. In addition, we found at least three bolides having hyperbolic orbits with high tensile strength values. Meter-sized meteoroids of interstellar origin could be more common than previously thought, representing about 1% of the flux of large bolides. The inferred bulk physical properties suggest that the interstellar medium could bias these projectiles towards high strength rocks with the ability to survive prolonged exposure to the harsh interstellar space conditions.

astro-ph.EP↗