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micrometre to sub-micrometre-scale alloys of platinum group elements (pges) known as refractory metal nuggets (rmns) have been observed in primitive meteorites. the australian synchrotron x-ray fluorescence (xrf) beamline, in tandem with the maia detector, allows rapid detection of pges in concentrations as low as 50-1... | in situ analysis of refractory metal nuggets in carbonaceous chondrites |
we used three different sets of arecibo delay-doppler radar images and five well-covered occultations to generate a revised three-dimensional shape model of asteroid (216) kleopatra with a spatial resolution of ∼10 km. we find kleopatra to be a bi-lobate contact binary of overall dimensions 276 × 94 × 78 km ± 15% and e... | a revised shape model of asteroid (216) kleopatra |
we examine how the history of phanerozoic marine biodiversity relates to environmental change. our focus is on north america, which has a relatively densely sampled history. by transforming time series into the time-frequency domain using wavelets, histories of biodiversity are shown to be similar to sea level, tempera... | timing and periodicity of phanerozoic marine biodiversity and environmental change |
purposeprecise delineation of organs at risk is a crucial task in radiotherapy treatment planning for delivering high doses to the tumor while sparing healthy tissues. in recent years, automated segmentation methods have shown an increasingly high performance for the delineation of various anatomical structures. howeve... | esophagus segmentation in ct via 3d fully convolutional neural network and random walk |
we have obtained polarimetric measurements of asteroid (101955) bennu, a presumably primitive near-earth object (neo) that is the target of nasa's sample return mission osiris-rex. during our observing campaign, bennu was visible from earth under a wide range of illumination conditions, with phase angle in the range 16... | unusual polarimetric properties of (101955) bennu: similarities with f-class asteroids and cometary bodies |
learning an unknown $n$-qubit quantum state $\rho$ is a fundamental challenge in quantum computing. information-theoretically, it is known that tomography requires exponential in $n$ many copies of $\rho$ to estimate it up to trace distance. motivated by computational learning theory, aaronson et al. introduced many (w... | private learning implies quantum stability |
pollution of white dwarf atmospheres may be caused by asteroids that originate from the locations of secular and mean-motion resonances in planetary systems. asteroids in these locations experience increased eccentricity, leading to tidal disruption by the white dwarf. we examine how the ν6 secular resonance shifts out... | on the role of resonances in polluting white dwarfs by asteroids |
context. stellar radial velocities play a fundamental role in the discovery of extrasolar planets and the measurement of their physical parameters as well as in the study of stellar physical properties.aims: we investigate the impact of the solar activity on the radial velocity of the sun using the harps spectrograph t... | long-term radial-velocity variations of the sun as a star: the harps view |
here we report on the significant role of a so far overlooked dynamical aspect, namely, a secular resonance between the dwarf planet ceres and other asteroids. we demonstrate that this type of secular resonance can be the dominant dynamical factor in certain regions of the main asteroid belt. specifically, we performed... | asteroid secular dynamics: ceres’ fingerprint identified |
we perform high-fidelity simulations of a wide-field telescopic survey searching for near-earth objects (neos) larger than 140 m, focusing on the observation and detection model, as well as detection efficiency and accuracy. as a test survey, we select the large synoptic survey telescope (lsst). we use its proposed poi... | high-fidelity simulations of the near-earth object search performance of the large synoptic survey telescope |
we present the first results of our survey of asteroid polarization phase curves in the near-infrared j and h bands using the wirc+pol instrument on the palomar 200-inch telescope. we confirm through observations of standard stars that wirc+pol can reach the 0.1% precision needed for asteroid phase curve characterizati... | asteroid polarimetric phase behavior in the near-infrared: s- and c-complex objects |
fragments of small solar system bodies entering earth's atmosphere have possibly been important contributors of organic compounds to the early earth. the cyano radical (cn) emission from meteors is considered as potentially one of the most suitable markers of organic compounds in meteoroids, however, its detection in m... | analysis of cn emission as a marker of organic compounds in meteoroids using laboratory simulated meteors |
the timing of formation of the first planetesimals determines the mode of planetary accretion and their geophysical and compositional evolution. astronomical observations of circumstellar disks and solar system geochronology provide evidence for planetesimal formation during molecular cloud collapse, much earlier than ... | rapid formation of exoplanetesimals revealed by white dwarfs |
a series of high pressure and temperature experiments were conducted to better constrain the fe isotope fractionation during core-mantle differentiation in planetesimal and planetary bodies. synthetic mixtures of oxides and metal having varying amounts of sulfur, approximating terrestrial and martian compositions, were... | sulfur-controlled iron isotope fractionation experiments of core formation in planetary bodies |
oxygen is the dominant element in our planetary system. it is therefore remarkable that it shows substantial isotopic diversity both in mass-dependent fractionation, because it is a light element, and in mass-independent fractionation, primarily associated with variation in abundance of 16o. on earth, the primary varia... | oxygen isotopes and sampling of the solar system |
the origin of life on earth would benefit from a prebiotic atmosphere that produced nitriles, like hcn, which enable ribonucleotide synthesis. however, geochemical evidence suggests that hadean air was relatively oxidizing with negligible photochemical production of prebiotic molecules. these paradoxes are resolved by ... | origin-of-life molecules in the atmosphere after big impacts on the early earth |
rimmed grooves, lineations and elongate craters around mare imbrium shape much of the nearside moon. this pattern was coined the imbrium sculpture, and it was originally argued that it must have been formed by a giant oblique (~30°) impact, a conclusion echoed by later studies. some investigators, however, noticed that... | origin and implications of non-radial imbrium sculpture on the moon |
wd 1145+017 is currently the only white dwarf known to exhibit periodic transits of planetary debris as well as absorption lines from circumstellar gas. we present the first simultaneous fast optical spectrophotometry and broad-band photometry of the system, obtained with the gran telescopio canarias (gtc) and the live... | fast spectrophotometry of wd 1145+017 |
context. near-earth objects (neos), thanks to their proximity, provide a unique opportunity to investigate asteroids with diameters down to dozens of meters. the study of neos is also important because of their potential hazard to the earth. the investigation of small neos is challenging from earth as they are observab... | photometric survey of 55 near-earth asteroids |
the double asteroid redirection test (dart) is a nasa-sponsored mission that will be the first direct test of the kinetic impactor technique for planetary defense. the dart spacecraft will impact into didymos-b, the moon of the binary system 65803 didymos, and the resulting period change will be measured from earth. im... | benchmarking impact hydrocodes in the strength regime: implications for modeling deflection by a kinetic impactor |
we present the identification and preliminary analysis of a dust trail following the orbit of (3200) phaethon as seen in white-light images recorded by the wide-field imager for parker solar probe (wispr) instrument on the nasa parker solar probe (psp) mission. during psp's first solar encounter in 2018 november, a dus... | parker solar probe observations of a dust trail in the orbit of (3200) phaethon |
the influence of fe concentration on heat transport properties of olivine was investigated to understand the cooling history of rocky planets such as mercury, mars and asteroids. thermal conductivity (λ) and thermal diffusivity (κ) were measured simultaneously for olivine polycrystal with different fe contents (fo, fo9... | effect of iron content on thermal conductivity of olivine with implications for cooling history of rocky planets |
gaseous circumbinary disks (cbds) that are highly inclined to the binary orbit are commonly observed in nature. these disks harbor particles that can reach large mutual inclinations as a result of nodal precession once the gas disk has dissipated. with n-body simulations that include fragmentation we demonstrate that m... | misaligned circumbinary disks as efficient progenitors of interstellar asteroids |
context. we assess statistical inversion of asteroid rotation periods, pole orientations, shapes, and phase curve parameters from photometric lightcurve observations, here sparse data from the esa gaia space mission (data release 2) or dense and sparse data from ground-based observing programs.aims: assuming general co... | asteroid lightcurve inversion with bayesian inference |
we designed a plate impact shock recovery experiment to simulate the starting materials and shock conditions associated with the only known natural quasicrystals, in the khatyrka meteorite. at the boundaries among cual5, (mg0.75fe2+0.25)2sio4 olivine, and the stainless steel chamber walls, the recovered specimen contai... | shock synthesis of quasicrystals with implications for their origin in asteroid collisions |
from mid-ordovician ~470 myr-old limestone >100 fossil l-chondritic meteorites have been recovered, representing the markedly enhanced flux of meteorites to earth following the breakup of the l-chondrite parent body. recently one anomalous meteorite, österplana 065 (öst 65), was found in the same beds that yield l c... | a new type of solar-system material recovered from ordovician marine limestone |
medical time series are sequential data collected over time that measures health-related signals, such as electroencephalography (eeg), electrocardiography (ecg), and intensive care unit (icu) readings. analyzing medical time series and identifying the latent patterns and trends that lead to uncovering highly valuable ... | self-supervised contrastive learning for medical time series: a systematic review |
the helicopter vibrations generated by the main rotor/gearbox assembly are the principal cause of damage to cockpit instruments and discomfort of the crew in terms of cabin noise. the principal path of vibration transmission to the fuselage is through the gearbox rigid support struts. with the aim of reducing these vib... | development of a high-performance low-weight hydraulic damper for active vibration control of the main rotor on helicopters—part 1: design and mathematical model |
as technology continues to evolve, our society is becoming enriched with more intelligent devices that help us perform our daily activities more efficiently and effectively. one of the most significant technological advancements of our time is the internet of things (iot), which interconnects various smart devices (suc... | smart transportation: an overview of technologies and applications |
field-free magnetization switching by in-plane current injection via spin-orbit interactions in heavy-metal/ferromagnet bilayer systems is of great interest for applications of spin-orbit torque (sot). here, we demonstrate theoretically how to deterministically switch the magnetization of cofeb with a tilted perpendicu... | deterministic magnetization switching by spin-orbit torque in a ferromagnet with tilted magnetic anisotropy: a macrospin modeling |
this study has introduced a predictive framework including a heuristic guidance law named predictive path planning and multiple-horizon multiple-model predictive control as the control scheme for soft landing on an irregular-shaped asteroid. the dynamical model of spacecraft trajectory around an asteroid is introduced.... | soft landing on an irregular shape asteroid using multiple-horizon multiple-model predictive control |
02.18.1930 a new body was discovered beyond the orbit of neptune. pluto is quite a large body rotates around the sun and is not a single on its orbit. that is why international astronomical union (iau) by its resolution of 24.08.2006 gave this "large" planet lower status. it was one of several new objects which are cal... | dwarf planets (to the 10th anniversary of the introduction of the new class of planets) |
determining the shapes of a rotating liquid droplet bound by surface tension is an archetypal problem in the study of the equilibrium shapes of a spinning and charged droplet, a problem that unites models of the stability of the atomic nucleus with the shapes of astronomical-scale, gravitationally-bound masses. the sha... | artificial tektites: an experimental technique for capturing the shapes of spinning drops |
we describe the mineralogy, petrology and oxygen isotopic compositions of high-temperature rims around mineralogically pristine calcium-aluminum-rich inclusions (cais) from the cr, cb and ch carbonaceous chondrites. in cr chondrites, nearly all cais are surrounded by single- or multi-layered rims composed of cai-like m... | high-temperature rims around calcium-aluminum-rich inclusions from the cr, cb and ch carbonaceous chondrites |
the lunar cratering record is used to constrain the bombardment history of both the earth and the moon. however, it is suggested from different perspectives, including impact crater dating, asteroid dynamics, lunar samples, impact basin-forming simulations, and lunar evolution modelling, that the moon could be missing ... | large impact cratering during lunar magma ocean solidification |
treatment protocols combining tamsulosin and solifenacin proved better management of the complicated urinary tract symptoms. the pharmaceutical preparations of tamsulosin and solifenacin suffered from the high difference in their ratio, 0.4 mg tamsulosin and 6 mg solifenacin, and strong spectral overlap. here, we devel... | smart uv spectrophotometric methods based on simple mathematical filtration and classical methods for the simultaneous determination of tamsulosin and solifenacin: a comparative study of efficacy and spectral resolution |
so far, only two interstellar objects have been observed within our solar system. while the first one, 1i/`oumuamua, had asteroidal characteristics, the second one, 2i/borisov, showed clear evidence of cometary activity. we performed polarimetric observations of comet 2i/borisov using the european southern observatory ... | unusual polarimetric properties for interstellar comet 2i/borisov |
we simulate the passage through the sun-jupiter system of interstellar objects (isos) similar to 1i/`oumuamua or 2i/borisov. capture of such objects is rare and overwhelmingly from low incoming speeds on to orbits akin to those of known long-period comets. this suggests that some of these comets could be of extrasolar ... | capture of interstellar objects: a source of long-period comets |
in this study, we measured bidirectional reflectance spectra (0.5-4.0 μm) of 24 cms, five crs, one ci, one cv, and one c2 carbonaceous chondrites. these meteorites are known to have experienced an important variability in their relative degrees of aqueous alteration degree (rubin et al. [2007]. geochim. cosmochim. acta... | bidirectional reflectance spectroscopy of carbonaceous chondrites: implications for water quantification and primary composition |
many if not most small asteroids are rubble piles covered by regolith, and small perturbations may be enough to disturb their surfaces in complex ways due to microgravity. experiments to study low-gravity regolith dynamics are challenging, and properly validated numerical simulations can provide valuable insights. in t... | numerical simulations of oscillation-driven regolith motion: brazil-nut effect |
trajectory design in highly-perturbed environments like binary asteroids is challenging. it typically requires using realistic, non-autonomous dynamical models in which periodic solutions derived in autonomous systems vanish. in this work, lagrangian descriptors are employed in the perturbed planar bi-elliptic restrict... | finding regions of bounded motion in binary asteroid environment using lagrangian descriptors |
in recent years, noncontact measurements of vital signs using cameras received a great amount of interest. however, some questions are unanswered: (i) which vital sign is monitored using what type of camera? (ii) what is the performance and which factors affect it? (iii) which health issues are addressed by camera-base... | continuous monitoring of vital signs using cameras: a systematic review |
in this study we generate optimal runge-kutta (rk) schemes for converging the artificial compressibility method (acm) using dual time-stepping with high-order unstructured spatial discretizations. we present optimal rk schemes with between s = 2 and s = 7 stages for spectral difference (sd) and discontinuous galerkin (... | optimal runge-kutta schemes for pseudo time-stepping with high-order unstructured methods |
chondrites are rocky fragments of asteroids that formed at different times and heliocentric distances in the early solar system. most chondrite groups contain water-bearing minerals, attesting that both water-ice and dust were accreted on their parent asteroids. nonetheless, the hydrogen isotopic composition (d/h) of w... | origin of hydrogen isotopic variations in chondritic water and organics |
superbolides, i.e. extremely bright meteors produced by entries of meter-sized bodies into terrestrial atmosphere, are rare events. we present here detailed analysis of a superbolide, which occurred over romania on january 7, 2015. the trajectory, velocity, and orbit were determined using two all-sky photographs from a... | the january 7, 2015, superbolide over romania and structural diversity of meter-sized asteroids |
the osiris-rex asteroid sample return mission is the third mission in national aeronautics and space administration (nasa)'s new frontiers program and is the first u.s. mission to return samples from an asteroid to earth. the most important decision ahead of the osiris-rex team is the selection of a prime sample-site o... | overcoming the challenges associated with image-based mapping of small bodies in preparation for the osiris-rex mission to (101955) bennu |
there has been speculation about a class of relativistic explosions with an initial lorentz factor γinit smaller than that of classical gamma-ray bursts (grbs). these “dirty fireballs” would lack prompt grb emission but could be pursued via their optical afterglow, appearing as transients that fade overnight. here we r... | iptf archival search for fast optical transients |
(3200) phaethon is a compelling object as it has an asteroidal appearance and spectrum, produces a weak dust tail during perihelion at just 0.14 au, and is the parent body of the geminid meteor shower. a better understanding of the physical properties of phaethon is needed to understand the nature of its current and pr... | rotationally resolved spectroscopic characterization of near-earth object (3200) phaethon |
1i/’oumuamua was discovered by the panoramic survey telescope and rapid response system (pan-starrs 1) on 2017 october 19. unlike all previously discovered minor planets, this object was determined to have eccentricity e > 1.0, suggesting an interstellar origin. since this discovery and within the limited window of ... | constraints on the density and internal strength of 1i/’oumuamua |
secondary organic aerosols (soas) play a key role in climate change and air quality. determining the fundamental parameters that distribute organic compounds between the phases is essential, as atmospheric lifetime and impacts change drastically between the gas and particle phase. in this work, gas-to-particle partitio... | gas-to-particle partitioning of major biogenic oxidation products: a study on freshly formed and aged biogenic soa |
the decay of radioactive 26al to 26mg (half-life of 730,000 years) is postulated to have been the main energy source promoting asteroidal melting and differentiation in the nascent solar system. high-resolution chronological information provided by the 26al-26mg decay system is, therefore, intrinsically linked to the t... | accretion timescales and style of asteroidal differentiation in an 26al-poor protoplanetary disk |
any effort which intends to physically interact with specific asteroids requires understanding at least of the composition and multi-scale structure of the surface layers, sometimes also of the interior. therefore, it is necessary first to characterize each target object sufficiently by a precursor mission to design th... | capabilities of gossamer-1 derived small spacecraft solar sails carrying mascot-derived nanolanders for in-situ surveying of neas |
the active contour model (acm) is a standard image analysis technique whose numerous variants have attracted an enormous amount of research attention across multiple fields. incorrectly, however, the acm's differential-equation-based formulation and prototypical dependence on user initialization have been regarded as b... | end-to-end deep convolutional active contours for image segmentation |
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 ... | cohesive regolith on fast rotating asteroids |
resonance capture is studied numerically in the three-body problem for arbitrary inclinations. massless particles are set to drift from outside the 1:5 resonance with a jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. randomly constructed samples explore parameter space f... | resonance capture at arbitrary inclination |
the potentially hazardous asteroid (185851) 2000 dp107 was the first binary near-earth asteroid to be imaged. radar observations in 2000 provided images at 75 m resolution that revealed the shape, orbit, and spin-up formation mechanism of the binary. the asteroid made a more favorable flyby of the earth in 2008, yieldi... | radar imaging and characterization of the binary near-earth asteroid (185851) 2000 dp107 |
here, we evaluate the extent of aqueous alteration among five pristine specimens of the ungrouped tagish lake carbonaceous chondrite (tl5b, tl11h, tl11i, tl4, and tl10a) using thermogravimetric analysis (tga) and infrared (ir) transmission spectroscopy. both tga and ir spectroscopy have proven to be reliable methods fo... | water abundance in the tagish lake meteorite from tga and ir spectroscopy: evaluation of aqueous alteration |
the detached object sedna is likely at the inner edge of the oort cloud, more precisely the inner oort cloud (ioc). until recently it was the sole member of this population. the recent discovery of the detached object 2012 vp113 has confirmed that there should be more objects in this region. three additional ioc candid... | re-assessing the formation of the inner oort cloud in an embedded star cluster - ii. probing the inner edge |
we review previously published and newly obtained crater size-frequency distributions in the inner solar system. these data indicate that the moon and the terrestrial planets have been bombarded by two populations of objects. population 1, dominating at early times, had nearly the same size distribution as the present-... | the inner solar system cratering record and the evolution of impactor populations |
since 1996, the nasa/jet propulsion laboratory on-line horizons system has provided open access to the latest jpl orbit solutions through customizable ephemeris generation and searches. currently, high-precision ephemerides for more than 683,000 objects are available: all known solar system bodies, several dozen spacec... | status of the jpl horizons ephemeris system |
the first multimodal emotion recognition challenge (mer 2023) was successfully held at acm multimedia. the challenge focuses on system robustness and consists of three distinct tracks: (1) mer-multi, where participants are required to recognize both discrete and dimensional emotions; (2) mer-noise, in which noise is ad... | mer 2023: multi-label learning, modality robustness, and semi-supervised learning |
from small seeds falling from trees to asteroids colliding with planets and moons, the impact of projectiles onto granular targets occurs in nature at different scales. in this paper, we investigate open questions in the mechanics of granular cratering, in particular, the forces acting on the projectile and the roles o... | roles of packing fraction, microscopic friction, and projectile spin in cratering by impact |
c-type asteroids are the source of the carbonaceous chondrite meteorites and represent remnants of primitive planetesimals that formed at the outer margins of the early solar system and may have delivered volatiles to the inner solar system, in particular the early earth. however, the nature of carbonaceous chondrites ... | insight into multi-step geological evolution of c-type asteroids from ryugu particles |
hayabusa2 spacecraft successfully collected rock samples from the surface of c-type near-earth asteroid 162173 ryugu through two touchdowns and brought them back to earth in 2020. at the extraterrestrial sample curation center in jaxa, we performed initial description of all samples to obtain fundamental information an... | variations of the surface characteristics of ryugu returned samples |
context. asteroid families are the outcomes of disruption or cratering events on a size and energy scales that are not reproducible in laboratory experiments. overall structure, as well as properties of individual members, in the old families could have been changed since their formation. therefore young families prese... | the young datura asteroid family. spins, shapes, and population estimate |
the samples returned from a c-type asteroid (ryugu) by the hayabusa2 mission constitute unprecedented access to carbonaceous material never exposed to earth's atmosphere that may still contain phases formed in the earliest stages of the solar system. we present an extensive analysis of a large set of grains and bulks o... | constraints on solar system early evolution by micromega analysis of ryugu carbonates |
we found that sdss j094002.56+274942.0 underwent a superoutburst in 2019 february based on our observations and zwicky transient facility (ztf) data. this object showed shallow eclipses during this superoutburst and we established the orbital period to be 0.1635015(1) d in combination with the ztf and asteroid terrestr... | sdss j094002.56+274942.0: an su uma star with an orbital period of 3.92 hours and an apparently unevolved secondary |
near-earth asteroid 99942 apophis presents a unique opportunity to study the dynamics, bulk properties, and interior structure of a rubble-pile asteroid when it makes its close encounter with the earth in 2029. in order to better understand the potential outcomes of a tidal encounter between earth and apophis, and to s... | using a discrete element method to investigate seismic response and spin change of 99942 apophis during its 2029 tidal encounter with earth |
aims: we investigate the spectra, material properties, and orbital distribution of millimeter- to decimeter-sized meteoroids. our study aims to distinguish the characteristics of populations of differently sized meteoroids and reveal the heterogeneity of identified meteoroid streams. we verify the surprisingly large ra... | spectral and orbital survey of medium-sized meteoroids |
context. over the past decades, several interplanetary missions have studied small bodies in situ, leading to major advances in our understanding of their geological and geophysical properties. these missions, however, have had a limited number of targets. among them, the nasa dawn mission has characterised in detail t... | closing the gap between earth-based and interplanetary mission observations: vesta seen by vlt/sphere |
we present "tracklet-less heliocentric orbit recovery" (thor), an algorithm for linking of observations of solar system objects across multiple epochs that does not require intranight tracklets or a predefined cadence of observations within a search window. by sparsely covering regions of interest in the phase space wi... | thor: an algorithm for cadence-independent asteroid discovery |
aeolian erosion is a destructive process that can erode small-size planetary objects through their interaction with a gaseous environment. aeolian erosion operates in a wide range of environments and under various conditions. aeolian erosion has been extensively explored in the context of geophysics in terrestrial plan... | the aeolian-erosion barrier for the growth of metre-size objects in protoplanetary discs |
aims: to interpret adaptive-optics observations of (216) kleopatra, we need to describe an evolution of multiple moons orbiting an extremely irregular body and include their mutual interactions. such orbits are generally non-keplerian and orbital elements are not constants.methods: consequently, we used a modified n-bo... | an advanced multipole model for (216) kleopatra triple system |
object detection and tracking are challenging tasks for resource-constrained embedded systems. while these tasks are among the most compute-intensive tasks from the artificial intelligence domain, they are only allowed to use limited computation and memory resources on embedded devices. in the meanwhile, such resource-... | skynet: a hardware-efficient method for object detection and tracking on embedded systems |
we report on the first polarimetric study of (3200) phaethon, the target of jaxa's destiny+ mission, in the negative branch to ensure its anhydrous nature and to derive an accurate geometric albedo. we conducted observations at low phase angles (sun-target-observer angle, α = 8.8-32.4°) from 2021 october to 2022 januar... | (3200) phaethon polarimetry in the negative branch: new evidence for the anhydrous nature of the destiny+ target asteroid |
in this paper, we show that the constant-dimensional weisfeiler-leman algorithm for groups (brachter & schweitzer, lics 2020) can be fruitfully used to improve parallel complexity upper bounds on isomorphism testing for several families of groups. in particular, we show: - groups with an abelian normal hall subgrou... | on the parallel complexity of group isomorphism via weisfeiler-leman |
the cm carbonaceous chondrites provide unique insights into the composition of the protoplanetary disk, and the accretion and geological history of their parent c complex asteroid(s). of the hundreds of cms that are available for study, the majority are finds and so may have been compromised by terrestrial weathering. ... | cm carbonaceous chondrite falls and their terrestrial alteration |
implantation of ions in minerals by high energy radiation is an important process in planetary and materials sciences. for example, the solar wind is a multi-ion flux that progressively modifies the composition and structure of near-surface domains in solar objects, like asteroids. a bombardment of a target by differen... | an experimental study of proton implantation in olivine |
we report on the mineralogy, petrography, and o and al-mg isotopic systematics of secondary mineralization in the metasomatically altered igneous ca,al-rich inclusions (cais) [compact type a (cta), b1, b2, forsterite-bearing b (fob), and c] from the cv3 carbonaceous chondrite allende. this alteration affected mainly me... | infiltration metasomatism of the allende coarse-grained calcium-aluminum-rich inclusions |
asteroid-sized bodies are predicted to have been scattered throughout the solar system following gravitational interactions with the giant planets. this process could have delivered water-rich small bodies to the inner solar system. however, evidence from the meteorite record supporting this scattering is limited due t... | evidence for asteroid scattering and distal solar system solids from meteorite paleomagnetism |
we present a fast method to calculate an asteroid survey's 'bias' - essentially a correction factor from the observed number of objects to the actual number in the population. the method builds upon the work of jedicke and metcalfe (jedicke, r., metcalfe, t.s. [1998]. icaurs 131, 245-260) and granvik et al. (granvik, m... | a fast method for quantifying observational selection effects in asteroid surveys |
k. w. smith, queen's university, belfast; and l. denneau, university of hawaii, on behalf of the "asteroid terrestrial-impact last alert system" (atlas) team, report the serendipitous discovery of unusual activity associated with the inner main-belt minor planet (6478), which appears to have developed a lengthening tai... | (6478) gault |
observational evidence of white dwarf planetary systems is dominated by the remains of exo-asteroids through accreted metals, debris discs, and orbiting planetesimals. however, exo-planets in these systems play crucial roles as perturbing agents, and can themselves be perturbed close to the white dwarf roche radius. he... | orbital relaxation and excitation of planets tidally interacting with white dwarfs |
though rare, asteroid impacts are inevitable, and with the current state of technology, kinetic impactors are the preferred but not the complete solution. if the time to impact is short, or the threatening body too large, nuclear deflection serves as a final option. this work is part of an integrated study by national ... | options and uncertainties in planetary defense: impulse-dependent response and the physical properties of asteroids |
multiple sources of evidence suggest that asteroids ranging from hundreds meters to few kilometers in size are rubble piles, i.e. gravitational aggregates of loosely consolidated material. however, no direct data on their internal structure is available to date. cohesion between rubble-pile building blocks has been inv... | interior of top-shaped asteroids with cohesionless surface |
for those with access to even a modest telescope and ccd camera, this new and improved guide delivers all the information needed to take part in the scientific study of asteroids and variable stars. new techniques in photometry continue to be refined, and expert brian warner covers the developing territory in detail fo... | a practical guide to lightcurve photometry and analysis |
the design of an attitude control system for an asteroid-orbiting satellite via immersion and invariance is the subject of this paper. it is assumed that the asteroid is rotating with a constant rate, and that the inertia parameters of the satellite and the coefficients in the spherical harmonic gravitational potential... | quaternion-based adaptive attitude control of asteroid-orbiting spacecraft via immersion and invariance |
most of the major planets in the solar system support populations of co-orbiting bodies, known as trojans, at their l4 and l5 lagrange points. in contrast, earth has only one known co-orbiting companion. this paper presents the results from a search for earth trojans (ets) using the decam instrument on the blanco teles... | search for l5 earth trojans with decam |
ammonium-bearing minerals have been suggested to be present on mars, ceres, and various asteroids and comets. we undertook a systematic study of the spectral reflectance properties of ammonium-bearing minerals and compounds that have possible planetary relevance (i.e., ammonium carbonates, chlorides, nitrates, oxalates... | reflectance spectroscopy (0.35-8 μm) of ammonium-bearing minerals and qualitative comparison to ceres-like asteroids |
microtektites represent high-velocity/distal meteorite impact ejecta. demonstrating that microtektites found at several locations throughout east-antarctica consist of a homogeneous class of geological objects belonging to the australasian tektite/microtektite strewn field is fundamental to define the actual extent of ... | multi-collector 40ar/39ar dating of microtektites from transantarctic mountains (antarctica): a definitive link with the australasian tektite/microtektite strewn field |
we obtained thorough photometric observations of two binary near-earth asteroids (66391) moshup = 1999 kw4 and (88710) 2001 sl9 taken from 2000 to 2019. we modeled the data and derived physical and dynamical properties of the binary systems. for (66391) 1999 kw4, we derived its mutual orbit's pole, semimajor axis and e... | a satellite orbit drift in binary near-earth asteroids (66391) 1999 kw4 and (88710) 2001 sl9 - indication of the byorp effect |
every year, around 28,100 journals publish 2.5 million research publications. search engines, digital libraries, and citation indexes are used extensively to search these publications. when a user submits a query, it generates a large number of documents among which just a few are relevant. due to inadequate indexing, ... | multi-label classification of research articles using word2vec and identification of similarity threshold |
interactions of the solar wind and emitted photoelectrons with airless bodies have been studied extensively. however, the details of how charged particles interact with the regolith at the scale of a single grain have remained largely uncharacterized. recent efforts have focused upon determining total surface charge un... | grain-scale supercharging and breakdown on airless regoliths |
destiny+ is a flyby mission of asteroid phaethon proposed for jaxa/isas epsilon class small program with a launch target in 2022. mission overview is presented. | destiny+ mission: flyby of geminids parent asteroid (3200) phaethon and in-situ analyses of dust accreting on the earth |
simulated space weathering experiments on volatile-rich carbonaceous chondrites (ccs) have resulted in contrasting spectral behaviors (e.g. reddening vs bluing). the aim of this work is to investigate the origin of these contrasting trends by simulating space weathering on a subset of minerals found in these meteorites... | simulated space weathering of fe- and mg-rich aqueously altered minerals using pulsed laser irradiation |
the four massive galilean satellites are believed to have formed within a circumplanetary disk during the last stages of jupiter’s formation. while the existence of a circum-jovian disk is supported by hydrodynamic simulations, no consensus exists regarding the origin and delivery mechanisms of the building blocks of t... | saturn’s formation and early evolution at the origin of jupiter’s massive moons |
aims: asteroid (31) euphrosyne is one of the biggest objects in the asteroid main belt and it is also the largest member of its namesake family. the euphrosyne family occupies a highly inclined region in the outer main belt and contains a remarkably large number of members, which is interpreted as an outcome of a disru... | binary asteroid (31) euphrosyne: ice-rich and nearly spherical |
this paper describes a new, analytic, and mechanistic model for calculating the effective thermal conductivity (keff) of planetary regolith, or any porous granular medium consisting of solid particles and gas (or vacuum). the model computes keff as a function of the physical properties of its components (e.g., intrinsi... | a mechanistic model for the thermal conductivity of planetary regolith: 1. the effects of particle shape, composition, cohesion, and compression at depth |
we have identified a star, epic 249706694 (hd 139139), that was observed during k2 campaign 15 with the kepler extended mission that appears to exhibit 28 transit-like events over the course of the 87-d observation. the unusual aspect of these dips, all but two of which have depths of 200 ± 80 ppm, is that they exhibit... | the random transiter - epic 249706694/hd 139139 |
the orbit-attitude hovering means that both the position and attitude of the spacecraft are kept to be stationary in the asteroid body-fixed frame. the orbit-attitude hovering is discussed in the framework of the gravitationally coupled orbit-attitude dynamics, also called the full dynamics, in which the spacecraft is ... | body-fixed orbit-attitude hovering control over an asteroid using non-canonical hamiltonian structure |
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