Paul Sánchez
Colorado Center for Astrodynamics Research
Cohesion (chemistry)PilePhysicsGravitationvan der Waals forceGeologyGeotechnical engineeringMaterials scienceCondensed matter physicsRubbleStrontium titanatePopulationRegolithSolar SystemDopingMechanicsAsteroidClassical mechanicsGeophysicsAstrobiology
Publications 49
#1Paul Sánchez (Colorado Center for Astrodynamics Research)H-Index: 16
#2Daniel D. Durda (SwRI: Southwest Research Institute)H-Index: 26
Last. R. DisslyH-Index: 3
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Abstract null null A series of experiments have been conducted to study the failure behavior of columns and piles comprised of cohesive fine powders in 1 g as a proxy for those which might occur in the agglomerated asteroid structure composed of cm-m size pebbles and boulders in a microgravity environment. Initially symmetrical piles of fine powders, under gravitation or centrifugal stress, develop features similar to those observed on asteroids, such as slide planes and finer cohesive structure...
#1Paul Sánchez (Colorado Center for Astrodynamics Research)H-Index: 16
#2Mathieu Renouf (University of Montpellier)H-Index: 14
Last. Frédéric Dubois (University of Montpellier)H-Index: 35
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Abstract Over the last decades, simulations by discrete elements methods (DEM) have proven to be a reliable analysis tool in various domains of science and engineering. By providing access to the local physical mechanisms, DEM allows the exploration of microscopic based phenomena related to particles properties and interactions in various conditions and to revisit constitutive equations consequently. The growing computer power and memory now allow us to handle large collections of grains of vari...
#1Paul Sánchez (Colorado Center for Astrodynamics Research)H-Index: 16
#3Emilien Azéma (Institut Universitaire de France)H-Index: 21
#1Esteban Wright (UR: University of Rochester)H-Index: 2
#2Alice C. Quillen (UR: University of Rochester)H-Index: 67
Last. Stephen R. Schwartz (UA: University of Arizona)H-Index: 18
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Abstract Spin off events and impacts can eject boulders from an asteroid surface and rubble pile asteroids can accumulate from debris following a collision between large asteroids. These processes produce a population of gravitational bound objects in orbit that can impact an asteroid surface at low velocity and with a distribution of impact angles. We present laboratory experiments of low velocity spherical projectiles into a fine granular medium, sand. We delineate velocity and impact angles g...
3 CitationsSource
#1Paul Sánchez (Colorado Center for Astrodynamics Research)H-Index: 16
#2Daniel J. Scheeres (CU: University of Colorado Boulder)H-Index: 79
Abstract The migration of cohesive regolith on the surface of an otherwise monolithic or strong asteroid is studied using theoretical and simulation models. The theory and simulations show that under an increasing spin rate (such as due to the YORP effect), the regolith covering is preferentially lost across certain regions of the body. For regolith with little or no cohesive strength, failure occurs by landsliding from the mid latitudes of the body at high enough spin rates. As the cohesive str...
12 CitationsSource
#1Esteban Wright (UR: University of Rochester)H-Index: 2
#2Alice C. Quillen (UR: University of Rochester)H-Index: 67
Last. Erik Asphaug (UA: University of Arizona)H-Index: 54
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We consider how an impact generated seismic pulse affects the surface of an asteroid distant from the impact site. With laboratory experiments on dry polydisperse gravel mixtures, we track the trajectories of particles ejected from the surface by a single strong upward propagating pressure pulse. High speed video images show that ejecta trajectories are independent of particle size, and collisions primarily take place upon landing. When they land particles are ballistically sorted, as proposed b...
3 CitationsSource
#1Daniel Hestroffer (Paris Observatory)H-Index: 43
#2Paul Sánchez (CU: University of Colorado Boulder)H-Index: 16
Last. Hajime YanoH-Index: 28
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Asteroids and other Small Solar System Bodies (SSSBs) are of high general and scientific interest in many aspects. The origin, formation, and evolution of our Solar System (and other planetary systems) can be better understood by analysing the constitution and physical properties of small bodies in the Solar System. Currently, two space missions (Hayabusa2, OSIRIS-REx) have recently arrived at their respective targets and will bring a sample of the asteroids back to Earth. Other small body missi...
14 CitationsSource
#1Esteban WrightH-Index: 2
#2Alice C. QuillenH-Index: 67
Last. Erik AsphaugH-Index: 54
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#1Alice C. Quillen (UR: University of Rochester)H-Index: 67
#2Katelyn J. Wagner (UR: University of Rochester)H-Index: 1
Last. Paul Sánchez (Colorado Center for Astrodynamics Research)H-Index: 16
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Using a damped mass-spring model, we simulate wobble of spinning homogeneous viscoelastic ellipsoids undergoing non-principal axis rotation. Energy damping rates are measured for oblate and prolate bodies with different spin rates, spin states, viscoelastic relaxation timescales, axis ratios, and strengths. Analytical models using a quality factor by Breiter et al. (2012) and for the Maxwell rheology by Frouard & Efroimsky (2018) match our numerical measurements of the energy dissipation rate af...
4 CitationsSource
#1Daniel J. Scheeres (CU: University of Colorado Boulder)H-Index: 79
#2Jay W. McMahon (CU: University of Colorado Boulder)H-Index: 18
Last. Osiris-Rex TeamH-Index: 6
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The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during th...
88 CitationsSource