Yarkovsky Effect Research Articles

Detectability of the Yarkovsky Effect in the Main Belt

We attempt to detect a signal of Yarkovsky-related acceleration in the orbits of 134 main belt asteroids (MBAs) we observed with the University of Hawai’i 88 inch telescope, supplemented with observations publicly available from the Minor Planet Center and Gaia Data Release 3. We estimated the expected Yarkovsky acceleration values based on parameters derived through thermophysical modeling, but we were not able to find any reliable detections of Yarkovsky in our sample. Through tests with synthetic observations, however, we estimated the minimum observational arc length needed to detect the Yarkovsky effect for all of our sample MBAs, which in nearly every case exceeded the current arc length of the existing observations. We find that the Yarkovsky effect could be detectable within a couple of decades of discovery for a 100 m MBA assuming 0.″1 astrometric accuracy, which is at the size range detectable by the upcoming Vera Rubin Observatory Legacy Survey of Space and Time.

Influence of Planetary Encounters on the Magnitude of the Yarkovsky Effect in Asteroid Dynamics

Influence of Planetary Encounters on the Magnitude of the Yarkovsky Effect in Asteroid Dynamics

Peculiar Orbital Characteristics of Earth Quasi-Satellite 469219 Kamo‘oalewa: Implications for the Yarkovsky Detection and Orbital Uncertainty Propagation

469219 Kamo‘oalewa is selected as one of the primary targets of Tianwen-2 mission, which is currently believed to be the most stable quasi-satellite of Earth. Here we derive a weak detection of the Yarkovsky effect for Kamo‘oalewa, giving A 2 = (−1.075 ± 0.447) × 10−13 au day−2, with the available ground-based optical observations from Minor Planet Center and a relatively conservative weighting scheme. Due to the quasi-satellite resonance with Earth, we show that the detection of the Yarkovsky effect by orbital fitting with astrometric observations becomes difficult, as its orbital drift shows a slow oscillatory growth resulting from the Yarkovsky effect. In addition, we extensively explore the characteristics of orbital uncertainty propagation and find that the positional uncertainty mainly arises from the geocentric radial direction in 2010–2020 and then concentrates in the heliocentric transverse direction in 2020–2030. Furthermore, the heliocentric transverse uncertainty is clearly monthly dependent, which can arrive at a minimum around January and a maximum around July as the orbit moves toward the leading and trailing edges, respectively, in 2025–2027. Finally, we investigate a long-term uncertainty propagation in the quasi-satellite regime, implying that the quasi-satellite resonance with Earth may play a crucial role in constraining the increase of uncertainty over time. Such an interesting feature further implies that the orbital precision of Kamo‘oalewa is relatively stable at its quasi-satellite phase, which may also be true for other quasi-satellites of Earth.

Influence of Planetary Encounters on the Magnitude of the Yarkovsky Effect in Asteroid Dynamics

The influence of the solar radiation pressure and the Yarkovsky effect on the long-term orbital dynamics is estimated for a number of asteroids experiencing successive planetary encounters. The variation in the asteroid’s proper rotation period due to its approach to the planet and its effect on the asteroid’s further orbital dynamics through the Yarkovsky effect is considered. It is shown that close planetary encounters of small asteroids (tens of meters in diameter) with short rotation period (less than 10 h), which change the asteroid’s rotation period by several hours, significantly affect the magnitude of the Yarkovsky effect.

О возмущениях во вращательном движении астероида при его тесном сближении с Землей

By means of numerical simulation of the rotational dynamics of the asteroid (99942)Apophis, the perturbations occurring in the rotational motion of asteroids during their close approaches to the Earth are studied. It has been established that such events can lead to significant changes in the asteroid's own rotation velocity and the orientation of its rotation axis in space. The dependences of the change in the period of rotation of the asteroid on the parameters of the orbit and its rotational state before approaching the Earth are studied. It is shown that disturbances in the rotational motion of an asteroid that occur during approaches significantly affect its further orbital dynamics by changing the magnitude of the Yarkovsky effect.

The low surface thermal inertia of the rapidly rotating near-Earth asteroid 2016 GE1

Context. Asteroids smaller than about 100 m in diameter are observed to rotate very fast, with periods often much shorter than the critical spin limit of 2.2 h. Some of these super-fast rotators can also achieve a very large semimajor axis drift induced by the Yarkovsky effect, which, in turn, is determined by internal and surface physical properties. Aims. We consider here a small super-fast-rotating near-Earth asteroid, designated as 2016 GE1. This object rotates in just about 34 s, and a large Yarkovsky effect has been determined from astrometry. By using these results, we aim to constrain the thermal inertia of the surface of this extreme object. Methods. We used a recently developed statistical method to determine the thermal properties of near-Earth asteroids. The method is based on the comparison between the observed and the modeled Yarkovsky effect, and the thermal conductivity (inertia) is determined via a Monte Carlo approach. Parameters of the Yarkovsky effect model are fixed if their uncertainty is negligible, modeled with a Gaussian distribution of the errors if they are measured, or deduced from general properties of the population of near-Earth asteroids when they are unknown. Results. Using a well-established orbit determination procedure, we determined the Yarkovsky effect on 2016 GE1 and confirm a significant semimajor axis drift rate. Using a statistical method, we show that this semimajor axis drift rate can only be explained by low thermal inertia values below 100 J m−2 K−1 s−1/2. We benchmarked our statistical method using the well-characterized asteroid Bennu and find that only knowing the semimajor axis drift rate and the rotation period is generally insufficient for determining the thermal inertia. However, when the statistical method is applied to super-fast rotators, we find that the measured Yarkovsky effect can be achieved only for very low values of thermal inertia: namely, 90% of the probability density function of the model outcomes is contained at values smaller than 100 J m−2 K−1 s−1/2. Conclusions. We propose two possible interpretations for the extremely low thermal inertia of 2016 GE1: a high porosity or a cracked surface, or a thin layer of fine regolith on the surface. Though both possibilities seem somewhat unexpected, this opens up the possibility of a subclass of low-inertia, super-fast-rotating asteroids.

Reconstruction of asteroid spin states from Gaia DR3 photometry

Aims. Gaia Data Release 3 contains accurate photometric observations of more than 150 000 asteroids covering a time interval of 34 months. With a total of about 3 000 000 measurements, a typical number of observations per asteroid ranges from a few to several tens. We aimed to reconstruct the spin states and shapes of asteroids from this dataset. Methods. We computed the viewing and illumination geometry for each individual observation and used the light curve inversion method to find the best-fit asteroid model, which was parameterized by the sidereal rotation period, the spin axis direction, and a low-resolution convex shape. To find the best-fit model, we ran the inversion for tens of thousands of trial periods on interval 2–10 000 h, with tens of initial pole directions. To find the correct rotation period, we also used a triaxial ellipsoid model for the shape approximation. Results. In most cases the number of data points was insufficient to uniquely determine the rotation period. However, for about 8600 asteroids we were able to determine the spin state uniquely together with a low-resolution convex shape model. This large sample of new asteroid models enables us to study the spin distribution in the asteroid population. The distribution of spins confirms previous findings that (i) small asteroids have poles clustered toward ecliptic poles, likely because of the YORP-induced spin evolution, (ii) asteroid migration due to the Yarkovsky effect depends on the spin orientation, and (iii) members of asteroid families have the sense of rotation correlated with their proper semimajor axis: over the age of the family, orbits of prograde rotators evolved, due to the Yarkovsky effect, to larger semimajor axes, while those of retrograde rotators drifted in the opposite direction.

Measuring the Orbit Drift of Near-Earth Asteroids by the Yarkovsky Effect

The Yarkovsky effect causes the semimajor axis drift of near-Earth asteroids. The drift can be detected by a precise orbit determination process. Using the proposed algorithm, 2233 out of 27,078 near-Earth asteroids are chosen as the initial candidates. Out of these initial candidates, 769 have a measurable Yarkovsky effect with a signal-to-noise ratio (S/N) larger than 1, and 166 have a measurable Yarkovsky effect with an S/N larger than 3. The ratio between retrograde and prograde near-Earth asteroids is plotted with respect to their size. An average ratio of 2 is found for asteroids with an absolute magnitude between 14 and 21. The measurement work is carried out based on orbit determination software developed by the authors that considers a high-precision dynamical model.

GaiaData Release 3

Context.The third data release by theGaiamission of the European Space Agency (DR3) is the first release to provide the community with a large sample of observations for more than 150 thousand Solar System objects, including asteroids and natural planetary satellites. The release contains astrometry (over 23 million epochs) and photometry, along with average reflectance spectra of 60518 asteroids and osculating elements.Aims.We present an overview of the procedures that have been implemented over several years of development and tests to process Solar System data at the level of accuracy thatGaiacan reach. We illustrate the data properties and potential with some practical examples.Methods.In order to allow the users ofGaiaDR3 to best exploit the data, we explain the assumptions and approaches followed in the implementation of the data processing pipeline for Solar System processing, and their effects in terms of data filtering, optimisation, and performances. We then test the data quality by analysing post-fit residuals to adjusted orbits, the capacity of detecting subtle dynamical effects (wobbling due to satellites or shape and Yarkovsky acceleration), and to reproduce known properties of asteroid photometry (phase curves and rotational light curves).Results.The DR3 astrometric accuracy is a clear improvement over the data published in DR2, which concerned a very limited sample of asteroids. The performance of the data reduction is met, and is illustrated by the capacity of detecting milliarcsecond-level wobbling of the asteroid photocentre that is due to satellite or shape effects and contributes to Yarkovsky effect measurements.Conclusions.The third data release can in terms of data completeness and accuracy be considered the first full-scale realisation of the Solar System survey byGaia.

Dark Comets? Unexpectedly Large Nongravitational Accelerations on a Sample of Small Asteroids

We report statistically significant detections of nonradial, nongravitational accelerations based on astrometric data in the photometrically inactive objects 1998 KY26, 2005 VL1, 2016 NJ33, 2010 VL65, 2016 RH120, and 2010 RF12. The magnitudes of the nongravitational accelerations are greater than those typically induced by the Yarkovsky effect, and there is no radiation-based, nonradial effect that can be so large. Therefore, we hypothesize that the accelerations are driven by outgassing and calculate implied H2O production rates for each object. We attempt to reconcile outgassing-induced acceleration with the lack of visible comae or photometric activity via the absence of surface dust and low levels of gas production. Although these objects are small, and some are rapidly rotating, the surface cohesive forces are stronger than the rotational forces, and rapid rotation alone cannot explain the lack of surface debris. It is possible that surface dust was removed previously, perhaps via outgassing activity that increased the rotation rates to their present-day value. We calculate dust production rates of order ∼10−4 g s−1 in each object, assuming that the nuclei are bare, within the upper limits of dust production from a sample stacked image of 1998 KY26 of g s−1. This production corresponds to brightness variations of order ∼0.0025%, which are undetectable in extant photometric data. We assess the future observability of each of these targets and find that the orbit of 1998 KY26—which is also the target of the extended Hayabusa2 mission—exhibits favorable viewing geometry before 2025.

(523599) 2003 RM: The Asteroid that Wanted to be a Comet

We report a statistically significant detection of nongravitational acceleration on the subkilometer near-Earth asteroid (523599) 2003 RM. Due to its orbit, 2003 RM experiences favorable observing apparitions every 5 yr. Thus, since its discovery, 2003 RM has been extensively tracked with ground-based optical facilities in 2003, 2008, 2013, and 2018. We find that the observed plane-of-sky positions cannot be explained with a purely gravity-driven trajectory. Including a transverse nongravitational acceleration allows us to match all observational data, but its magnitude is inconsistent with perturbations typical of asteroids such as the Yarkovsky effect or solar radiation pressure. After ruling out that the orbital deviations are due to a close approach or collision with another asteroid, we hypothesize that this anomalous acceleration is caused by unseen cometary outgassing. A detailed search for evidence of cometary activity with archival and deep observations from the Panoramic Survey Telescope and Rapid Response System and the Very Large Telescope does not reveal any detectable dust production. However, the best-fitting H2O sublimation model allows for brightening due to activity consistent with the scatter of the data. We estimate the production rate required for H2O outgassing to power the acceleration and find that, assuming a diameter of 300 m, 2003 RM would require Q(H2O) ∼ 1023 molec s−1 at perihelion. We investigate the recent dynamical history of 2003 RM and find that the object most likely originated in the mid-to-outer main belt (∼86% probability) as opposed to from the Jupiter-family comet region (∼11% probability). Further observations, especially in the infrared, could shed light on the nature of this anomalous acceleration.

The orbital evolution of Atira asteroids

ABSTRACT Asteroids having perihelion distance q < 1.3 AU are classified as near-Earth objects (NEOs), which are divided into different sub-groups: Vatira-class, Atira-class, Aten-class, Apollo-class, and Amor-class. 2020 AV2, the first Vatira (Orbiting totally inside Venus’ orbit) was discovered by the Twilight project of the Zwicky Transient Facility (ZTF) on 2020 January 4. Upon the discovery of 2020 AV2, a couple of orbital studies of the short-term orbital evolution of 2020 AV2 have been performed and published (e.g. de la Fuente Marcos & de la Fuente Marcos 2020; Greenstreet 2020). In this work, we performed an assessment of the long-term orbital evolution of known near-Earth objects and known Atiras under the Yarkovsky effect by using the Mercury6 N-body code. We considered not only planetary gravitational perturbation but also the non-gravitational Yarkovsky effect. Our calculation shows that the NEOs have generally two dynamical populations, one short-lived and the other long-lived. From our calculation, the transfer probabilities of Atira-class asteroids to Vatira-class asteroids for the first transition are ∼13.1 ± 0.400, ∼13.05 ± 0.005, and ∼13.25 ± 0.450 ${{\ \rm per\ cent}}$ for different values of the Yarkovsky force (i.e. obliquity of 0, 90, and 180 deg), respectively. It suggests that the radiation force may play some role in the long-term evolution of this asteroid population. Finally, our statistical study implicates that there should be 8.14 ± 0.133 Atira-class asteroids and 1.05 ± 0.075 Vatira-asteroids of the S-type taxonomy.

Yarkovsky effect detection from ground-based astrometric data for near-Earth asteroid (469219) Kamo’oalewa

Context. The Yarkovsky effect is a weak non-gravitational force but may significantly affect sub-kilometre-sized near-Earth asteroids. Yarkovsky-related drift may be detected, in principle, from astrometric or radar datasets of sufficient duration. To date, the asteroid Kamo’oalewa, the most stable of Earth’s quasi-satellites, has an ~18 yr-long arc of ground-based optical astrometry. These data provide an opportunity to detect the Yarkovsky effect acting on the asteroid Kamo’oalewa. Aims. We determined the Yarkovsky-related drift of asteroid Kamo’oalewa from ~18 yr of ground-based optical astrometry. Furthermore, we investigated the influence of the Yarkovsky effect on the orbital evolution of asteroid Kamo’oalewa based on this estimated value, and evaluated the potential improvements in the detection of non-gravitational accelerations (Yarkovsky effect and solar radiation pressure) for the asteroid Kamo’oalewa that could be provided by the future Chinese small-body exploration mission, Tianwen-2. Methods. The Yarkovsky-related drift of asteroid Kamo’oalewa was detected from the orbital fitting of the astrometry measurements. We checked the Yarkovsky effect detection based on both the orbit fitting results and the physical mechanisms of the Yarkovsky effect. Results. We report for the first time the detection of the Yarkovsky effect acting on asteroid Kamo’oalewa based on ~18 yr of ground-based optical astrometry data. The estimated semi-major axis drift is (−6.155 ± 1.758) × 10−3 au Myr−1. In addition, our numerical simulation shows that the Yarkovsky effect has almost no influence on the short-term orbital evolution of the asteroid Kamo’oalewa, but does have a long-term influence, by delaying the entry of the object into the Earth co-orbital region and accelerating its exit from this region, with a more significant signature on the exit than on the entry. In the context of spacecraft tracking data, the Tianwen-2 mission will improve both non-gravitational accelerations (Yarkovsky effect and solar radiation pressure) and predictions of its future ephemeris.

Trojan asteroids and the co-orbital dust ring of Venus

Context. Co-orbital asteroids have been thought to be the possible source of the zodiacal dust ring around the orbit of Venus, but the conclusions about the orbital stability and thus about the existence of Venus Trojans are inconsistent in the literature. Aims. We present a systematic survey of the orbital stability of Venus Trojans that takes the dynamical influences from General Relativity and the Yarkovsky effect into account. Methods. The orbits of thousands of fictitious Venus Trojans were simulated numerically. Using a frequency analysis, we describe their orbital stabilities and the dynamical mechanisms behind them. The influences of General Relativity and of the Yarkovsky effect, which were previously either neglected or oversimplified, were investigated in long-term numerical simulations. Results. The stability maps on the (a0, i0) plane and (a0, e0) plane are depicted, and the most stable Venus Trojans are found to occupy low-inclination horseshoe orbits with low eccentricities. The resonances that carve the fine structures in the stability map are determined. General Relativity decreases the stability of orbits only little, but the Yarkovsky effect may drive nearly all Venus Trojans out of the Trojan region in a relatively short time. Conclusions. The Venus Trojans have a poor orbital stability and cannot survive to the age of the Solar System. The zodiacal dust ring found around the orbit of Venus is more likely a sporadic phenomenon, as the result of a temporary capture into the 1:1 mean motion resonance of dust particles that were probably produced by passing comets or asteroids, but not by Venus Trojans.

The diurnal Yarkovsky effect of irregularly shaped asteroids

The Yarkovsky effect plays an important role in the motions of small celestial bodies. Increasingly detailed observations bring the need for high-accuracy modelling of the effect. We used the multiphysics software COMSOL to model the diurnal Yarkovsky effect in three dimensions and compare the results with those derived from the widely adopted theoretical linear model. We find that the linear model shows high accuracy for spherical asteroids in most cases. We explored the range of parameters for which the relative error of the linear model is over 10%. For biaxial ellipsoidal asteroids (particularly oblate ones), the linear model systematically overestimates the transverse Yarkovsky force by ~10%. The diurnal effect on triaxial ellipsoids is periodic, and no linear model is available for this phenomenon. Our numerical calculations show that the average effects on triaxial ellipsoids are stronger than those on biaxial ellipsoids. We also investigated the diurnal effect on asteroids of real shapes and find it be overestimated by the linear model by 16% on average, with a maximum of up to 35%. To estimate the strength of the Yarkovsky effect directly from the shape, we introduced the quantity of ‘effective area’ for asteroids of any shape, and find a significant linear relationship between the Yarkovsky migration rate and the effective area. This brings great convenience to the estimation in practice.

The Yarkovsky Effect in REBOUNDx

To more thoroughly study the effects of radiative forces on the orbits of small, astronomical bodies, we introduce the Yarkovsky effect into reboundx, an extensional library for the N-body integrator rebound. Two different versions of the Yarkovsky effect (the “Full Version” and the “Simple Version”) are available for use, depending on the needs of the user. We provide demonstrations for both versions of the effect and compare their computational efficiency with another previously implemented radiative force. In addition, we show how this effect can be used in tandem with other features in reboundx by simulating the orbits of asteroids during the asymptotic giant branch phase of a 2 M ☉ star. This effect is made freely available for use with the latest release of reboundx.

Yarkovsky effect: Delivery of Asteroids to near earth orbits

Significant advances have been made in recent years and extensive studies are going for assisting theasteroids’ destiny. From these studies, we hope to obtain a much better understanding of the influenceof the non-gravitational forces on the asteroids, and the overall history of the solar system. At the sametime, Yarkovsky effect is important in terms of impact hazard. Both the pure scientific concerns, and theimpact hazardous point of view concentrated on the need of developing reliable plans of impactevidence, require a major struggle in order to improve the current knowledge of the size of theYarkovsky affection on these objects. In this article, a brief description of Yarkovsky effect is presented,and the delivery of NEAs to near Earth orbits as well.

Influence of the Yarkovsky Effect on Mean Motion Resonances of Asteroids with Small Perihelion Distances

Influence of the Yarkovsky Effect on Mean Motion Resonances of Asteroids with Small Perihelion Distances

GENGA. II. GPU Planetary N-body Simulations with Non-Newtonian Forces and High Number of Particles

We present recent updates and improvements of the graphical processing unit (GPU) N-body code GENGA. Modern state-of-the-art simulations of planet formation require the use of a very high number of particles to accurately resolve planetary growth and to quantify the effect of dynamical friction. At present the practical upper limit is in the range of 30,000–60,000 fully interactive particles; possibly a little more on the latest GPU devices. While the original hybrid symplectic integration method has difficulties to scale up to these numbers, we have improved the integration method by (i) introducing higher level changeover functions and (ii) code improvements to better use the most recent GPU hardware efficiently for such large simulations. We added treatments of non-Newtonian forces such as general relativity, tidal interaction, rotational deformation, the Yarkovsky effect, and Poynting–Robertson drag, as well as a new model to treat virtual collisions of small bodies in the solar system. We added new tools to GENGA, such as semi-active test particles that feel more massive bodies but not each other, a more accurate collision handling and a real-time openGL visualization. We present example simulations, including a 1.5 billion year terrestrial planet formation simulation that initially started with 65,536 particles, a 3.5 billion year simulation without gas giants starting with 32,768 particles, the evolution of asteroid fragments in the solar system, and the planetesimal accretion of a growing Jupiter simulation. GENGA runs on modern NVIDIA and AMD GPUs.

Painting Asteroids for Planetary Defense

Asteroidal impact threats to the Earth will be predicted a century or more in advance. Changing an asteroid's albedo changes the force of Solar radiation on it, and hence its orbit. Albedo may be changed by applying a thin ($\sim 0.1\,\mu$) reflective coat of alkali metal, dispensed as vapor by an orbiting spacecraft. A complete coat reduces the effective Solar gravity, changing the orbital period. A Tunguska-class (50 m diameter) asteroid in a nominal orbit with perihelion 1 AU and aphelion 3 AU ($a = 2\,$AU, $e = 0.5$) may be displaced along its path by $\sim 1000\,$km in 100 years, sufficient to avoid impact in a populated area, by application of one kg of lithium or sodium metal over its entire surface. Alternatively, coating one hemisphere of an asteroid in an elliptical orbit may produce a Solar radiation torque, analogous to but distinct from the Yarkovsky effect, displacing it by an Earth radius in $\sim 200$ years. The time required scales as the square root of the asteroid's diameter (the 1/6 power of its mass) because the displacement increases quadratically with time, making it possible to prevent the catastrophic impact of a km-sized asteroid with a minimal mass.