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when rubble-pile asteroid 2008 tc3 impacted earth on 7 october 2008, the recovered rock fragments indicated that such asteroids can contain exogenic material1,2. however, spacecraft missions to date have only observed exogenous contamination on large, monolithic asteroids that are impervious to collisional disruption3,... | exogenic basalt on asteroid (101955) bennu |
we study the generation of primordial black holes (pbh) in a single field inflection point model of inflation wherein the effective potential is expanded up to the sextic order and the inversion symmetry is imposed such that only even powers are retained in the potential. such a potential allows the existence of an inf... | primordial black holes dark matter from inflection point models of inflation and the effects of reheating |
the relative differences in the degree of hydration should be reflected in any classification scheme for aqueously altered meteorites. here we report the bulk mineralogies and degree of hydration in 37 different carbonaceous chondrites: renazzo-like (cr), mighei-like (cm), and ungrouped (type 2) samples. this is achiev... | classification of hydrous meteorites (cr, cm and c2 ungrouped) by phyllosilicate fraction: psd-xrd modal mineralogy and planetesimal environments |
we present an experimental study on ion irradiation of carbonaceous chondrites, simulating solar wind irradiation on primitive asteroids, to better constrain the space weathering processes of low albedo objects. the irradiations were performed on pressed pellets of the cv allende, co frontier mountain 95002 and lancé, ... | ion irradiation of carbonaceous chondrites: a new view of space weathering on primitive asteroids |
we study the prospects of future gravitational wave (gw) detectors in probing primordial black hole (pbh) binaries. we show that across a broad mass range from 10-5 m⊙ to 107 m⊙, future gw interferometers provide a potential probe of the pbh abundance that is more sensitive than any currently existing experiment. in pa... | prospects for probing gravitational waves from primordial black hole binaries |
hayabusa2 arrived at the c-type asteroid ryugu in june 2018. during one and a half year of the ryugu-proximity operation, we succeeded in two rovers landing, one lander landing, two spacecraft touchdown/sample collection, one kinetic impact operation and two tiny reflective balls and one rover orbiting. among the two s... | hayabusa2 mission status: landing, roving and cratering on asteroid ryugu |
beyond-standard-model extensions of qcd could result in quark and gluon confinement occurring well above at temperature around the gev scale. these models can also alter the order of the qcd phase transition. therefore, the enhanced production of primordial black holes (pbhs) that can accompany the change in relativist... | signatures of a high temperature qcd transition in the early universe |
we investigate gravitational microlensing signals produced by a spatially extended object transiting in front of a finite-sized source star. the most interesting features arise for lens and source sizes comparable to the einstein radius of the setup. using this information, we obtain constraints from the subaru-hsc sur... | subaru-hsc through a different lens: microlensing by extended dark matter structures |
the surface strength of small rubble-pile asteroids, which are aggregates of unconsolidated material under microgravity, is poorly constrained but critical to understanding surface evolution and geologic history of the asteroid. here we use images of an impact ejecta deposit and downslope avalanche adjacent to a 70-m-d... | low surface strength of the asteroid bennu inferred from impact ejecta deposit |
a major challenge for gravitational-wave (gw) detection in the μ hz band is engineering a test mass (tm) with sufficiently low acceleration noise. we propose a gw detection concept using asteroids located in the inner solar system as tms. our main purpose is to evaluate the acceleration noise of asteroids in the μ hz b... | asteroids for μ hz gravitational-wave detection |
the composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early solar system. we present spectra of the nightingale crater region on near-earth asteroid bennu with a distinct infrared absorption around 3.4 micrometers. corresponding images of boulders s... | bright carbonate veins on asteroid (101955) bennu: implications for aqueous alteration history |
the concept of local climate zone (lcz) was developed to quantify the relationship between urban morphology and urban heat island (uhi) phenomenon. each lcz is supposed to represent homogeneous air temperature. however, there is inadequate data for verifying the air temperature differences between lcz classes. therefor... | investigating the relationship between local climate zone and land surface temperature using an improved wudapt methodology - a case study of yangtze river delta, china |
we investigate a possibility of primordial black hole (pbh) formation with a hierarchical mass spectrum in multiple phases of inflation. as an example, we find that one can simultaneously realize a mass spectrum that has recently attracted a lot of attention: stellar-mass pbhs (∼o (10 ) m⊙ ) as a possible source of bin... | primordial black hole tower: dark matter, earth-mass, and ligo black holes |
during its approach to asteroid (101955) bennu, nasa's origins, spectral interpretation, resource identification, and security-regolith explorer (osiris-rex) spacecraft surveyed bennu's immediate environment, photometric properties, and rotation state. discovery of a dusty environment, a natural satellite, or unexpecte... | the operational environment and rotational acceleration of asteroid (101955) bennu from osiris-rex observations |
we present the discovery of asassn-18ey (maxi j1820+070), a new black hole low-mass x-ray binary (lmxb) discovered by the all-sky automated survey for supernovae (asas-sn). a week after asas-sn discovered asassn-18ey as an optical transient, it was detected as an x-ray transient by maxi/gcs. here, we analyze asas-sn an... | asassn-18ey: the rise of a new black hole x-ray binary |
we describe a methodology of estimating the size-frequency distribution (sfd) of near-earth asteroids (neas). we estimate the completion versus size of present surveys based on the re-detection ratio, that is, the fraction of all detections over a recent period that are re-detections of already discovered objects rathe... | the population of near-earth asteroids |
impact glasses found in lunar soils provide a possible window into the impact history of the inner solar system. however, their use for precise reconstruction of this history is limited by an incomplete understanding of the physical mechanisms responsible for their origin and distribution and possible relationships to ... | constraining the formation and transport of lunar impact glasses using the ages and chemical compositions of chang'e-5 glass beads |
the earthcare satellite mission's objective is to retrieve profiles of aerosol and water cloud physical properties from measurements made by its cloud-profiling radar, backscattering lidar, and passive multi-spectral imager. these retrievals, together with other geophysical properties, are input into broadband (bb) rad... | broadband radiative quantities for the earthcare mission: the acm-com and acm-rt products |
the extraterrestrial materials returned from asteroid (162173) ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to ci (ivuna-type) carbonaceous chondrites. here, we show that high-temperature anhydrous primary minerals in ryugu and ci chon... | oxygen isotopes of anhydrous primary minerals show kinship between asteroid ryugu and comet 81p/wild2 |
burn markers are observed in many records of the cretaceous-paleogene asteroid impact and mass extinction event. these materials could be derived from wildfires on land or from sedimentary rocks hit by the asteroid. we present a detailed record of molecular burn markers (polycyclic aromatic hydrocarbons [pahs]) from th... | organic matter from the chicxulub crater exacerbated the k-pg impact winter |
current practice for asteroid close proximity maneuvers requires extremely accurate characterization of the environmental dynamics and precise spacecraft positioning prior to the maneuver. this creates a delay of several months between the spacecraft's arrival and the ability to safely complete close proximity maneuver... | terminal adaptive guidance via reinforcement meta-learning: applications to autonomous asteroid close-proximity operations |
evidence is mounting that the small bodies of our solar system, such as comets and asteroids, have at least partially inherited their chemical composition from the first phases of the solar system formation. it then appears that the molecular complexity of these small bodies is most likely related to the earliest stage... | astrochemical evolution along star formation: overview of the iram large program asai |
the osiris-rex camera suite (ocams) will acquire images essential to collecting a sample from the surface of bennu. during proximity operations, these images will document the presence of satellites and plumes, record spin state, enable an accurate model of the asteroid's shape, and identify any surface hazards. they w... | ocams: the osiris-rex camera suite |
spacecraft missions have observed regolith blankets of unconsolidated subcentimetre particles on stony asteroids1-3. telescopic data have suggested the presence of regolith blankets also on carbonaceous asteroids, including (101955) bennu4 and (162173) ryugu5. however, despite observations of processes that are capable... | fine-regolith production on asteroids controlled by rock porosity |
meteorites provide a unique insight into early solar system processes. however, to fully interpret this record requires that these meteorites are related back to their source asteroids and ultimately to the original planetesimal population that formed early in solar system history. as a first step in this process an as... | linking asteroids and meteorites to the primordial planetesimal population |
due to high metal values and raised difficulties in finding superficial deposits, the exploration for mineral resources needs to reach greater depths. to achieve this objective, integrating aster and 3d inversion of aeromagnetic can be a useful tool in imaging deep magnetic mineralization hosting-structures. in this st... | integration of aster satellite imagery and 3d inversion of aeromagnetic data for deep mineral exploration |
we propose and study the new (generalized) e-type α-attractor models of inflation, in order to include formation of primordial black holes (pbhs). the inflaton potential has a near-inflection point where slow-roll conditions are violated, thus leading to large scalar perturbations collapsing to pbhs later. an ultra-slo... | e-models of inflation and primordial black holes |
constraining the inflationary epoch is one of the aims of modern cosmology. in order to fully exploit current and future small-scale observations, it is necessary to devise tools to directly relate them to the early universe's dynamics. we present here a novel reverse engineering approach able to connect fundamental la... | primordial black hole dark matter from inflation: the reverse engineering approach |
comets have three known reservoirs: the roughly spherical oort cloud (for long-period comets), the flattened kuiper belt (for ecliptic comets), and, surprisingly, the asteroid belt (for main-belt comets). comets in the oort cloud were thought to have formed in the region of the giant planets and then placed in quasi-st... | origin and evolution of the cometary reservoirs |
spherex is a proposed smex mission selected for phase a. spherex will carry out the first all-sky spectral survey and provide for every 6.2" pixel a spectra between 0.75 and 4.18 $\mu$m [with r$\sim$41.4] and 4.18 and 5.00 $\mu$m [with r$\sim$135]. the spherex team has proposed three specific science investigations to ... | science impacts of the spherex all-sky optical to near-infrared spectral survey: report of a community workshop examining extragalactic, galactic, stellar and planetary science |
ceres, the largest body in the asteroid belt (940 km diameter), provides a unique opportunity to study the interior structure of a volatile-rich dwarf planet. variations in a planetary body's subsurface rheology and density affect the rate of topographic relaxation. preferential attenuation of long wavelength topograph... | the interior structure of ceres as revealed by surface topography |
random bombardment by comets, asteroids and associated fragments form and alter the lunar regolith and other rocky surfaces. the accumulation of impact craters over time is of fundamental use in evaluating the relative ages of geologic units. crater counts and radiometric ages from returned samples provide constraints ... | quantifying crater production and regolith overturn on the moon with temporal imaging |
the relative proportion of the two isotopes of nitrogen, 14n and 15n, varies dramatically across the solar system, despite little variation on earth. nasa's genesis mission directly sampled the solar wind and confirmed that the sun -- and, by inference, the protosolar nebula from which the solar system formed -- is hig... | nitrogen isotope variations in the solar system |
carbonaceous meteorites are thought to be fragments of c-type (carbonaceous) asteroids. samples of the c-type asteroid (162173) ryugu were retrieved by the hayabusa2 spacecraft. we measured the mineralogy and bulk chemical and isotopic compositions of ryugu samples. the samples are mainly composed of materials similar ... | samples returned from the asteroid ryugu are similar to ivuna-type carbonaceous meteorites |
subduction zones represent the interface between earth's interior (crust and mantle) and exterior (atmosphere and oceans), where carbon and other volatile elements are actively cycled between earth reservoirs by plate tectonics. helium is a sensitive tracer of volatile sources and can be used to deconvolute mantle and ... | the helium and carbon isotope characteristics of the andean convergent margin |
on 2018 february 4.41, the all-sky automated survey for supernovae (asas-sn) discovered asassn-18bt in the k2 campaign 16 field. with a redshift of z = 0.01098 and a peak apparent magnitude of b max = 14.31, asassn-18bt is the nearest and brightest sne ia yet observed by the kepler spacecraft. here we present the disco... | seeing double: asassn-18bt exhibits a two-component rise in the early-time k2 light curve |
at least 25 {per cent} of white dwarfs show atmospheric pollution by metals, sometimes accompanied by detectable circumstellar dust/gas discs or (in the case of wd 1145+017) transiting disintegrating asteroids. delivery of planetesimals to the white dwarf by orbiting planets is a leading candidate to explain these phen... | unstable low-mass planetary systems as drivers of white dwarf pollution |
we derived 90% confidence limits (cls) on the interstellar number density ({ρ }{is}{cl}) of interstellar objects (isos; comets and asteroids) as a function of the slope of their size-frequency distribution (sfd) and limiting absolute magnitude. to account for gravitational focusing, we first generated a quasi-realistic... | an observational upper limit on the interstellar number density of asteroids and comets |
we present a real-time stamp classifier of astronomical events for the automatic learning for the rapid classification of events broker, alerce. the classifier is based on a convolutional neural network, trained on alerts ingested from the zwicky transient facility (ztf). using only the science, reference, and differen... | alert classification for the alerce broker system: the real-time stamp classifier |
the exploration of near-earth asteroids has revealed dynamic surfaces characterized by mobile, unconsolidated material that responds to local geophysical gradients, resulting in distinct morphologies and boulder distributions. the osiris-rex (origins, spectral interpretation, resource identification, and security-regol... | global patterns of recent mass movement on asteroid (101955) bennu |
asteroid (101955) bennu is a dark asteroid on an earth-crossing orbit that is thought to have assembled from the fragments of an ancient collision. we use spatially resolved visible and near-infrared spectra of bennu to investigate its surface properties and composition. in addition to a hydrated phyllosilicate band, w... | widespread carbon-bearing materials on near-earth asteroid (101955) bennu |
the dwarf planet (1) ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the sun of about 2.8 astronomical units (one astronomical unit is the earth-sun distance). thermal evolution models suggest that it is a differentiated body with pote... | sublimation in bright spots on (1) ceres |
we perform streaming-instability simulations at hill density and beyond to demonstrate that planetesimal formation is not completed when pebble accumulations exceed the local hill density. we find that hill density is not a sufficient criterion for further gravitational collapse of a pebble cloud into a planetesimal, b... | testing the jeans, toomre, and bonnor-ebert concepts for planetesimal formation: 3d streaming-instability simulations of diffusion-regulated formation of planetesimals |
landing on an asteroid is a highly valuable endeavor accompanied by significant challenges, making it a promising area for further research. this paper aims to present a flexible lander specifically designed for asteroid landing missions while also studying the guidance and control techniques involved in its descent ph... | position-attitude coupling guidance and control for asteroid landing with a flexible lander |
the tmt detailed science case describes the transformational science that the thirty meter telescope will enable. planned to begin science operations in 2024, tmt will open up opportunities for revolutionary discoveries in essentially every field of astronomy, astrophysics and cosmology, seeing much fainter objects muc... | thirty meter telescope detailed science case: 2015 |
since darpa grand challenges (rural) in 2004/05 and urban challenges in 2007, autonomous driving has been the most active field of ai applications. almost at the same time, deep learning has made breakthrough by several pioneers, three of them (also called fathers of deep learning), hinton, bengio and lecun, won acm tu... | autonomous driving with deep learning: a survey of state-of-art technologies |
"liciacube - the light italian cubesat for imaging of asteroids" is managed by the italian space agency (asi) and will be part of the nasa dart mission, with the aim of i) documenting the dart impact's effects on the secondary member of the (65803) didymos binary asteroid system, ii) characterizing the shape of the tar... | liciacube - the light italian cubesat for imaging of asteroids in support of the nasa dart mission towards asteroid (65803) didymos |
during slow-roll inflation, non-perturbative transitions can produce bubbles of metastable vacuum. these bubbles expand exponentially during inflation to super-horizon size, and later collapse into black holes when the expansion of the universe is decelerating. estimating the rate for these transitions during a time-de... | monochromatic mass spectrum of primordial black holes |
primordial black holes (pbhs) can generically form in inflationary setups through the collapse of enhanced cosmological perturbations, providing us access to the early universe through their associated observational signatures. in the current work we propose a new mechanism of pbh production within non-canonical inflat... | primordial black holes and gravitational waves from non-canonical inflation |
soon after their formation, the terrestrial planets experienced intense impact bombardment by comets, leftover planetesimals from primary accretion, and asteroids. this temporal interval in solar system evolution, termed late accretion, thermally and chemically modified solid planetary surfaces and may have impeded lif... | onset of giant planet migration before 4480 million years ago |
stochastic inflation resolves primordial perturbations nonlinearly, probing their probability distribution deep into its non-gaussian tail. the strongest perturbations collapse into primordial black holes. in typical black-hole-producing single-field inflation, the strongest stochastic kicks occur during a period of co... | stochastic constant-roll inflation and primordial black holes |
hydrogen occurs at the near percent level in the most hydrated chondrites (ci and cm) attesting to the presence of water in the asteroid-forming regions. their h abundances and isotopic signatures are powerful proxies for deciphering the distribution of h in the protoplanetary disk and the origin of earth's water. here... | hydrogen in chondrites: influence of parent body alteration and atmospheric contamination on primordial components |
ceres is the largest body in the asteroid belt with a radius of approximately 470 km. in part due to its large mass, ceres more closely approaches hydrostatic equilibrium than major asteroids. pre-dawn mission shape observations of ceres revealed a shape consistent with a hydrostatic ellipsoid of revolution. the dawn s... | constraints on ceres' internal structure and evolution from its shape and gravity measured by the dawn spacecraft |
frozen ground covers a vast area of the earth's surface and it has important ecohydrological implications for cold regions under changing climate. however, it is challenging to characterize the simultaneous transfer of mass and energy in frozen soils. within the modeling framework of simultaneous transfer of mass, mome... | understanding the mass, momentum, and energy transfer in the frozen soil with three levels of model complexities |
context. the gaia spacecraft of the european space agency (esa) has been securing observations of solar system objects (ssos) since the beginning of its operations. data release 2 (dr2) contains the observations of a selected sample of 14,099 ssos. these asteroids have been already identified and have been numbered by ... | gaia data release 2. observations of solar system objects |
we propose a new scenario for the formation of asteroid-mass primordial black holes (pbhs). our mechanism is based on the annihilation of the string-wall network associated with the breaking of a u(1) global symmetry into a discrete zn symmetry. if the potential has multiple local minima (n > 1) the network is stabl... | primordial black hole dark matter from catastrogenesis with unstable pseudo-goldstone bosons |
the field of mobile and wearable computing is undergoing a revolutionary integration of machine learning. devices can now diagnose diseases, predict heart irregularities, and unlock the full potential of human cognition. however, the underlying algorithms powering these predictions are not immune to biases with respect... | beyond accuracy: a critical review of fairness in machine learning for mobile and wearable computing |
the formation of asteroids, comets, and planets occurs in the interior of protoplanetary disks during the early phase of star formation. consequently, the chemical composition of the disk might shape the properties of the emerging planetary system. in this context, it is crucial to understand whether and what organic m... | first detection of the simplest organic acid in a protoplanetary disk |
white dwarfs that have accreted rocky planetary bodies provide unique insights regarding the bulk composition of exoplanetary material. the analysis presented here uses observed pollutant abundances to constrain both where in the planetary system the pollutant bodies originated, and the geological and collisional histo... | polluted white dwarfs: constraints on the origin and geology of exoplanetary material |
we make the case for studying the complexity of approximately simulating (sampling) quantum systems for reasons beyond that of quantum computational supremacy, such as diagnosing phase transitions. we consider the sampling complexity as a function of time t due to evolution generated by spatially local quadratic bosoni... | dynamical phase transitions in sampling complexity |
without a protective atmosphere, space-exposed surfaces of airless solar system bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. the return of samples from near-earth asteroid (162173) ryugu by hayabusa2 provides the first o... | a dehydrated space-weathered skin cloaking the hydrated interior of ryugu |
this paper proposes a revised definition for the entanglement cost of a quantum channel n . in particular, it is defined here to be the smallest rate at which entanglement is required, in addition to free classical communication, in order to simulate n calls to n , such that the most general discriminator cannot distin... | entanglement cost and quantum channel simulation |
there are four known sources of dust in the inner solar system: jupiter family comets, asteroids, halley type comets, and oort cloud comets. here we combine the mass, velocity, and radiant distributions of these cosmic dust populations from an astronomical model with a chemical ablation model to estimate the injection ... | sources of cosmic dust in the earth's atmosphere |
most comets are volatile-rich bodies that have recently entered the inner solar system following long-term storage in the kuiper belt and the oort cloud reservoirs. these reservoirs feed several distinct, short-lived "small body" populations. here, we present new measurements of the optical colors of cometary and comet... | color systematics of comets and related bodies |
the mass extinction of life 66 million years ago at the cretaceous/paleogene boundary, marked by the extinctions of dinosaurs and shallow marine organisms, is important because it led to the macroevolution of mammals and appearance of humans. the current hypothesis for the extinction is that an asteroid impact in prese... | global climate change driven by soot at the k-pg boundary as the cause of the mass extinction |
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 unce... | non-chondritic iron isotope ratios in planetary mantles as a result of core formation |
in all inflationary scenarios of primordial black hole (pbh) formation, amplified scalar perturbations inevitably accompany an induced stochastic gravitational wave background (isgwb) at smaller scales. in this paper, we study the isgwb originating from the inflationary model, introduced in our previous paper [n. bhaum... | small scale induced gravitational waves from primordial black holes, a stringent lower mass bound, and the imprints of an early matter to radiation transition |
noble gas isotopes are powerful tracers of the origins of planetary volatiles, and the accretion and evolution of the earth. the compositions of magmatic gases provide insights into the evolution of the earth’s mantle and atmosphere. despite recent analytical progress in the study of planetary materials and mantle-deri... | chondritic xenon in the earth’s mantle |
asteroids' and comets' geodesy is a challenging yet important task for planetary science and spacecraft operations, such as esa's hera mission tasked to look at the aftermath of the recent nasa dart spacecraft's impact on dimorphos. here we present a machine learning approach based on so-called geodesynets which learns... | geodesy of irregular small bodies via neural density fields |
the recent discovery by pan-starrs1 of 1i/2017 u1 (‘oumuamua), on an unbound and hyperbolic orbit, offers a rare opportunity to explore the planetary formation processes of other stars and the effect of the interstellar environment on a planetesimal surface. 1i/‘oumuamua’s close encounter with the inner solar system in... | col-ossos: colors of the interstellar planetesimal 1i/‘oumuamua |
asteroid (101955) bennu, the target of nasa's osiris-rex sample return mission, is a d ≈ 0.5 km diameter low albedo near-earth object. it has a spectral signature consistent with primitive carbonaceous chondrites, and an orbit similar to that of the earth. a plausible evolution scenario for bennu is that it migrated in... | in search of the source of asteroid (101955) bennu: applications of the stochastic yorp model |
asteroid surface exploration is challenging due to complex terrain topology and irregular gravity field. a hopping rover is considered as a promising mobility solution to explore the surface of small celestial bodies. conventional path planning tasks, such as traversing a given map to reach a known target, may become p... | path planning for asteroid hopping rovers with pre-trained deep reinforcement learning architectures |
dujmović et al. [\emph{j.~acm}~'20] recently proved that every planar graph is isomorphic to a subgraph of the strong product of a bounded treewidth graph and a path. analogous results were obtained for graphs of bounded euler genus or apex-minor-free graphs. these tools have been used to solve longstanding problems on... | graph product structure for non-minor-closed classes |
on december 3rd, 2014, the japanese space agency (jaxa) launched successfully the hayabusa2 (hy2) spacecraft to its journey to near earth asteroid (162173) ryugu. aboard this spacecraft is a compact landing package, mascot (mobile asteroid surface scout), which was developed by the german aerospace centre (dlr) in coll... | mascot—the mobile asteroid surface scout onboard the hayabusa2 mission |
the impact of an object on a granular solid is an ubiquitous phenomenon in nature, the scale of which ranges from the impact of a raindrop onto sand all the way to that of a large asteroid on a planet. despite the obvious relevance of these impact events, the study of the underlying physics mechanisms that guide them i... | impact on granular beds |
the first definitely interstellar object 1i/'oumuamua (previously a/2017 u1) observed in our solar system provides the opportunity to directly study material from an other star system. can such objects be intercepted? the challenge of reaching the object within a reasonable timeframe is formidable due to its high helio... | project lyra: sending a spacecraft to 1i/'oumuamua (former a/2017 u1), the interstellar asteroid |
samples of the carbonaceous asteroid ryugu were brought to earth by the hayabusa2 spacecraft. we analyzed 17 ryugu samples measuring 1 to 8 millimeters. carbon dioxide–bearing water inclusions are present within a pyrrhotite crystal, indicating that ryugu’s parent asteroid formed in the outer solar system. the samples ... | formation and evolution of carbonaceous asteroid ryugu: direct evidence from returned samples |
the induced gravitational wave (gw) background from enhanced primordial scalar perturbations is one of the most promising observational consequences of primordial black hole (pbh) formation from inflation. we investigate the induced gw spectrum ωigw from single-field inflation in the general ultra-slow-roll (usr) frame... | induced gravitational waves from the cosmic coincidence |
we study for the first time the possibility of probing long-range fifth forces utilizing asteroid astrometric data, via the fifth force-induced orbital precession. we examine nine near-earth object (neo) asteroids whose orbital trajectories are accurately determined via optical and radar astrometry. focusing on a yukaw... | novel constraints on fifth forces and ultralight dark sector with asteroidal data |
the solar system's dynamical state can be explained by an orbital instability among the giant planets. a recent model has proposed that the giant planet instability happened during terrestrial planet formation. this scenario has been shown to match the inner solar system by stunting mars' growth and preventing planet f... | the early instability scenario: terrestrial planet formation during the giant planet instability, and the effect of collisional fragmentation |
fast radio bursts (frbs) are newly discovered radio transient sources. their high dispersion measures indicate an extragalactic origin. however, due to the lack of observational data in other wavelengths, their progenitors still remain unclear. here we suggest that the collisions between neutron stars (nss) and asteroi... | fast radio bursts: collisions between neutron stars and asteroids/comets |
we explore the role of dissipative effects during warm inflation leading to the small-scale enhancement of the power spectrum of curvature perturbations. in this paper, we specifically focus on non-canonical warm inflationary scenarios and study a model of warm higgs-g inflation, in which the standard model higgs boson... | primordial black holes dark matter and secondary gravitational waves from warm higgs-g inflation |
the conditions, timing, and setting for the origin of life on earth and whether life exists elsewhere in our solar system and beyond represent some of the most fundamental scientific questions of our time. although the bombardment of planets and satellites by asteroids and comets has long been viewed as a destructive p... | the role of meteorite impacts in the origin of life |
the initial galactic velocity vector for the recently discovered hyperbolic asteroid 1i/'oumuamua (a/2017 u1) is calculated for before its encounter with our solar system. the latest orbit (jpl-13) shows that 'oumuamua has eccentricity > 1 at 944\sigma\, significance (1.19936 +- 0.00021), i.e. clearly unbound. assum... | kinematics of the interstellar vagabond 1i/‘oumuamua (a/2017 u1) |
we report on g-, r-, and i-band observations of the interstellar object 1i/‘oumuamua (1i) taken on 2017 october 29 from 04:28 to 08:40 utc by the apache point observatory (apo) 3.5 m telescope’s arctic camera. we find that 1i’s colors are g-r=0.41+/- 0.24 and r-i=0.23+/- 0.25, consistent with visible spectra and most c... | apo time-resolved color photometry of highly elongated interstellar object 1i/‘oumuamua |
the composition and physical properties of martian regolith are dramatically better understood compared to just a decade ago, particularly through the use of x-ray diffraction by the curiosity rover. because there are no samples of this regolith on earth, researchers and engineers rely on terrestrial simulants to test ... | mars global simulant mgs-1: a rocknest-based open standard for basaltic martian regolith simulants |
we report on the mineralogy, petrography, and in situ measured oxygen- and magnesium-isotope compositions of eight porphyritic chondrules (seven feo-poor and one feo-rich) from the renazzo-like carbonaceous (cr) chondrites graves nunataks 95229, grosvenor mountains 03116, pecora escarpment 91082, and queen alexandra ra... | distribution of 26al in the cr chondrite chondrule-forming region of the protoplanetary disk |
over the last decade, the solar wind has exhibited low densities and magnetic field strengths, representing anomalous states that have never been observed during the space age. as discussed by schwadron, blake, et al. (2014, https://doi.org/10.1002/2014sw001084), the cycle 23-24 solar activity led to the longest solar ... | update on the worsening particle radiation environment observed by crater and implications for future human deep-space exploration |
asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. they are also likely the sources of most of the water and other volatiles accreted by earth. in this review, we discuss t... | water reservoirs in small planetary bodies: meteorites, asteroids, and comets |
the osiris-rex thermal emission spectrometer (otes) will provide remote measurements of mineralogy and thermophysical properties of bennu to map its surface, help select the osiris-rex sampling site, and investigate the yarkovsky effect. otes is a fourier transform spectrometer covering the spectral range 5.71-100 μm (... | the osiris-rex thermal emission spectrometer (otes) instrument |
we derive purely gravitational constraints on dark matter and cosmic neutrino profiles in the solar system using asteroid (101955) bennu. we focus on bennu because of its extensive tracking data and high-fidelity trajectory modeling resulting from the osiris-rex mission. we find that the local density of dark matter is... | new constraints on dark matter and cosmic neutrino profiles through gravity |
studies of the lunar atmosphere have shown it to be a stable, low-density surface boundary exosphere for the last 3 billion years. however, substantial volcanic activity on the moon prior to 3 ga may have released sufficient volatiles to form a transient, more prominent atmosphere. here, we calculate the volume of mare... | lunar volcanism produced a transient atmosphere around the ancient moon |
the canadian space agency (csa) has contributed to the origins spectral interpretation resource identification security-regolith explorer (osiris-rex) spacecraft the osiris-rex laser altimeter (ola). the osiris-rex mission will sample asteroid 101955 bennu, the first b-type asteroid to be visited by a spacecraft. bennu... | the osiris-rex laser altimeter (ola) investigation and instrument |
we optimize a six degrees of freedom hovering policy using reinforcement meta-learning. the policy maps flash lidar measurements directly to on/off spacecraft body-frame thrust commands, allowing hovering at a fixed position and attitude in the asteroid body-fixed reference frame. importantly, the policy does not requi... | six degree-of-freedom body-fixed hovering over unmapped asteroids via lidar altimetry and reinforcement meta-learning |
context. it is well known that the magnetic activity of solar-type stars decreases with age, but it is widely debated in the literature whether there is a smooth decline or if there is an early sharp drop until 1-2 gyr that is followed by a relatively inactive constant phase.aims: we revisited the activity-age relation... | the solar twin planet search. the age-chromospheric activity relation |
extraterrestrial materials, including meteorites, interplanetary dust, and spacecraft-returned asteroidal and cometary samples, provide a record of the starting materials and early evolution of the solar system. we review how laboratory analyses of these materials provide unique information, complementary to astronomic... | astrophysics with extraterrestrial materials |
the periodic activity of the repeating fast radio burst (frb) 180916.j0158+65 was recently reported by the chime/frb collaboration team. from this source 28 bursts not only show a ∼16 day period with an active phase of ∼4.0 days, but they also exhibit a broken power law in differential energy distribution. in this lett... | periodic fast radio bursts as a probe of extragalactic asteroid belts |
the origins, spectral interpretation, resource identification, security-regolith explorer mission will return a sample to earth from asteroid (101955) bennu. digital terrain models (dtms) of the asteroid, and products enabled by them, are key to understanding the origin and evolution of the asteroid, providing geologic... | digital terrain mapping by the osiris-rex mission |
this study examines the history of the paradigm concerning a lunar (or solar-system-wide) terminal cataclysm (also called "late heavy bombardment" or lhb), a putative, brief spike in impacts at ~3.9 ga ago, preceded by low impact rates. we examine origin of the ideas, why they were accepted, and why the ideas are curre... | history of the terminal cataclysm paradigm: epistemology of a planetary bombardment that never (?) happened |
the planetary building blocks that formed in the terrestrial planet region were likely very dry, yet water is comparatively abundant on earth. here we review the various mechanisms proposed for the origin of water on the terrestrial planets. various in-situ mechanisms have been suggested, which allow for the incorporat... | the delivery of water during terrestrial planet formation |
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