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The past decade has brought major improvements in large-scale asteroid
discovery and characterization with over half a million known asteroids and
over 100,000 with some measurement of physical characterization. This explosion
of data has allowed us to create a new global picture of the Main Asteroid
Belt. Put in context with meteorite measurements...
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In this paper, we study the long-term dynamical evolution of highly elliptical orbits in the medium-Earth orbit region around the Earth. The real population consists primarily of Geosynchronous Transfer Orbits (GTOs), launched at specific inclinations, Molniya-type satellites and related debris. We performed a suite of long-term numerical integrati...
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... The number of asteroids in the asteroid belt larger than 1 km in diameter is estimated to be between 1 and 2 million 1 , making it the area of our Solar System with the majority of asteroids [1]. Studying these asteroids is crucial for several reasons, ranging from compositions and Solar System origin studies, to resource exploration, planetary defense, and impact and collision dynamics investigations [2,3,4]. ...
Low-thrust trajectories play a crucial role in optimizing scientific output and cost efficiency in asteroid belt missions. Unlike high-thrust transfers, low-thrust trajectories require solving complex optimal control problems. This complexity grows exponentially with the number of asteroids visited due to orbital mechanics intricacies. In the literature, methods for approximating low-thrust transfers without full optimization have been proposed, including analytical and machine learning techniques. In this work, we propose new analytical approximations and compare their accuracy and performance to machine learning methods. While analytical approximations leverage orbit theory to estimate trajectory costs, machine learning employs a more black-box approach, utilizing neural networks to predict optimal transfers based on various attributes. We build a dataset of about 3 million transfers, found by solving the time and fuel optimal control problems, for different time of flights, which we also release open-source. Comparison between the two methods on this database reveals the superiority of machine learning, especially for longer transfers. Despite challenges such as multi revolution transfers, both approaches maintain accuracy within a few percent in the final mass errors, on a database of trajectories involving numerous asteroids. This work contributes to the efficient exploration of mission opportunities in the asteroid belt, providing insights into the strengths and limitations of different approximation strategies.
... The number of asteroids in the asteroid belt larger than 1 km in diameter is estimated to be between 1 and 2 million 1 , making it the area of our Solar System with the majority of asteroids [1]. Studying these asteroids is crucial for several reasons, ranging from compositions and Solar System origin studies, to resource exploration, planetary defense, and impact and collision dynamics investigations [2,3,4]. ...
Low-thrust trajectories play a crucial role in optimizing scientific output and cost efficiency in asteroid belt missions. Unlike high-thrust transfers, low-thrust trajectories require solving complex optimal control problems. This complexity grows exponentially with the number of asteroids visited due to orbital mechanics intricacies. In the literature, methods for approximating low-thrust transfers without full optimization have been proposed, including analytical and machine learning techniques. In this work, we propose new analytical approximations and compare their accuracy and performance to machine learning methods. While analytical approximations leverage orbit theory to estimate trajectory costs, machine learning employs a more black-box approach , utilizing neural networks to predict optimal transfers based on various attributes. We build a dataset of about 3 million transfers, found by solving the time and fuel optimal control problems , for different time of flights, which we also release open-source. Comparison between the two methods on this database reveals the superiority of machine learning, especially for longer transfers. Despite challenges such as multi revolution transfers, both approaches maintain accuracy within a few percent in the final mass errors, on a database of trajectories involving numerous asteroids. This work contributes to the efficient exploration of mission opportunities in the asteroid belt, providing insights into the strengths and limitations of different approximation strategies.
... About 25% of our main belt objects have < 17.5, the completeness limit proposed in 2015 (Denneau et al., 2015), inhabiting the outer regions of the belt. Given that the outer belt is dominated by low albedo (typically ∼ 0.03, see DeMeo et al., 2015;Wright et al., 2016) C-class asteroids, a 1 km diameter asteroid in the outer belt would have ∼ 19.4, suggesting that it will take some time till the main belt is effectively complete for km-scale asteroids. ...
We present a new procedure to identify observations of known objects in large data sets of unlinked detections. It begins with a Keplerian integrals method that allows us to link two tracklets, computing preliminary orbits, even when the tracklets are separated in time by a few years. In the second step, we represent the results in a ‘graph’ where the tracklets are the nodes and the preliminary orbits are the edges. Then, acceptable ‘3-cycles’ are identified and a least squares orbit is computed for each of them. Finally, we construct sequences of n ≥ 4 tracklets by searching through the orbits of nearby 3-cycles and attempting to attribute the remaining tracklets. We calculate the technique’s efficiency at identifying unknown objects using real detections that attempt to mimic key parameters of the Minor Planet Center’s (MPC) Isolated Tracklet File (ITF) and then apply the procedure to the ITF. This procedure enables the recovery of several orbits, despite some having few tracklets per apparition. The MPC accepted > 95% of our linkages and most of the non-accepted linkages are 2-apparition linkages even when those linkages contained more than half a dozen tracklets.
... These grains eventually formed planetesimals through accretion; some planetesimals formed the planets we know today while others may have stopped growing at smaller sizes. The main-belt asteroids' compositions depend on where they were formed within the protoplanetary disk and how they were mixed in the early solar system (Morbidelli et al. 2009;DeMeo et al. 2015). Mixing may have occurred through planetary migration or through streaming instabilities Carrera et al. 2015). ...
Probing small main-belt asteroids provides insight into their formation and evolution through multiple dynamical and collisional processes. These asteroids also overlap in size with the potentially hazardous near-Earth object population and supply the majority of these objects. The Lucy mission will perform a flyby of the small main-belt asteroid, (152830) Dinkinesh, on 2023 November 1, in preparation for its mission to the Jupiter Trojan asteroids. In this Letter, we present data to support the planning of Lucy’s imminent encounter of Dinkinesh. We employed aperture photometry on stacked frames of Dinkinesh obtained by the Wide-field Infrared Survey Explorer and performed thermal modeling on a detection at 12 μ m to compute diameter and albedo values. Through this method, we determined Dinkinesh has an effective spherical diameter of 0.76 − 0.21 + 0.11 km and a visual geometric albedo of 0.27 − 0.06 + 0.25 at the 16th and 84th percentiles. This albedo is consistent with typical stony (S-type) asteroids. These measurements will enable the Lucy team to optimize planning for the flyby of Dinkinesh, including refinement of exposure times and flyby geometry. The data obtained from this mission will, in turn, allow us to better understand the calibration of our thermal models by providing ground truth data. The Lucy flyby presents a rare opportunity to study the smallest main-belt asteroid ever observed in situ.
... C-complex asteroids are the dominating population in the asteroid belt, representing ~60% of its mass Carry, 2014, 2013). They are typically linked to primitive, volatile-rich carbonaceous chondrites (e.g., DeMeo et al., 2015). These small bodies and all the derived cosmomaterials (meteorites, potentially some dust as Interplanetary Dust Particles and micro-meteorites) are thus key-objects to investigate the formation and evolution of the Solar System. ...
... It had a D-type asteroid reflectance spectrum [38,39,40], also similar to bare cometary nuclei observed at large solar distances; hence its origin as asteroid or an extinct cometary nucleus was uncertain. ...
The Oort cloud is thought to be a reservoir of icy planetesimals and the source of long-period comets (LPCs) implanted from the outer Solar System during the time of giant planet formation. The abundance of rocky ice-free bodies is a key diagnostic of Solar System formation models as it can distinguish between ``massive" and ``depleted" proto-asteroid belt scenarios and thus disentangle competing planet formation models. Here we report a direct observation of a decimeter-sized ($\sim2$ kg) rocky meteoroid on a retrograde LPC orbit ($e \approx 1.0$, i = $121^{\circ}$). During its flight, it fragmented at dynamic pressures similar to fireballs dropping ordinary chondrite meteorites. A numerical ablation model fit produces bulk density and ablation properties also consistent with asteroidal meteoroids. We estimate the flux of rocky objects impacting Earth from the Oort cloud to be $1.08^{+2.81}_{-0.95} \mathrm{meteoroids/10^6 km^2/yr}$ to a mass limit of 10 g. This corresponds to an abundance of rocky meteoroids of $\sim6^{+13}_{-5}$\% of all objects originating in the Oort cloud and impacting Earth to these masses. Our result gives support to migration-based dynamical models of the formation of the Solar System which predict that significant rocky material is implanted in the Oort cloud, a result not explained by traditional Solar System formation models.
... semi-major axis a = 269.5 au, period p = 4,424 yr, solution date 14 April 2021; https://ssd.jpl.nasa.gov/tools/sbdb_lookup. html#/?sstr=1996%20PW), it showed no cometary-like activity. It had a D-type asteroid reflectance spectrum [38][39][40] , also similar to bare cometary nuclei observed at large solar distances; hence, its origin as asteroid or an extinct cometary nucleus was uncertain. ...
The Oort cloud is thought to be a reservoir of icy planetesimals and the source of long-period comets (LPCs) implanted from the outer Solar System during the time of giant-planet formation. The abundance of rocky ice-free bodies is a key diagnostic of Solar System formation models as it can distinguish between ‘massive’ and ‘depleted’ proto-asteroid-belt scenarios and thus disentangle competing planet formation models. Here we report a direct observation of a decimetre-sized (~2 kg) rocky meteoroid on a retrograde LPC orbit (eccentricity ~1.0, inclination 121°). During its flight, it fragmented at dynamic pressures similar to fireballs dropping ordinary chondrite meteorites. A numerical ablation model fit produces bulk density and ablation properties also consistent with asteroidal meteoroids. We estimate the flux of rocky objects impacting Earth from the Oort cloud to be 1.08−0.95+2.81 meteoroids per 106 km2 yr−1 to a mass limit of 10 g. This corresponds to an abundance of rocky meteoroids of ~6−5+13% of all objects originating in the Oort cloud and impacting Earth to these masses. Our result gives support to migration-based dynamical models of the formation of the Solar System, which predict that significant rocky material is implanted in the Oort cloud, a result not explained by traditional Solar System formation models. Observations of a meteoroid coming from the Oort cloud show that it is made of rocky and not icy material, constraining the ratio of rocky to icy objects impacting Earth from the Oort cloud to 6−5+13%.
... Though some meteorites come from the Moon and Mars and it is possible that some of the least processed meteorite types (rich in carbon) originated in comets, the diversity of meteorite types is evidence for the diversity of asteroids. Some meteorite types have been linked to asteroid taxonomic classes by reflectance spectroscopy, but for many types, the link remains uncertain (DeMeo et al., 2015). ...
The following chapter provides an overview of the international regime definition, its ontological and normative commitments, regime formation, emergence and evolution as a distinct formation of knowledge, genealogically tracing how it has been conditioned or ‘made possible’. The insight generated in regime theory is then applied to space. The proposition that a cluster of similarly minded (responsible cosmopolitan) states can trigger regime formation is argued to be consistent with this insight, and regime theory may supply ample suggestions and yardsticks for a successful regime design. That said, it also points to caveats, notably in terms of regime leakage, and to the need to acknowledge and work around the observation that international regimes often make the exercise of power invisible but do not erase it, becoming instead its conduits.KeywordsInternational regime theoryRealismLiberalismRegime formationInternational securitySpace politicsPlanetary defenceSpace mining
... We now provide a brief review of asteroid belt science including relevant information to our discussion in the sections that follow. For a thorough review of asteroids, see Michel et al. (2015), specifically the sections of DeMeo et al. (2015) and Nesvorný et al. (2015). ...
... Asteroids are not distributed entirely uniformly due to the grav- itational perturbations of the other planets. These perturbations produce what are known as Kirkwood gaps at locations in resonance with Jupiter's orbit (Moons 1996;DeMeo et al. 2015). The Kirkwood gaps divide the asteroid belt into three discernible regions: the inner belt consisting of asteroids whose semi-major axes are less than 2.5 AU, the middle belt consisting of asteroids whose semimajor axes are between 2.5 and 2.8 AU, and the outer belt consisting of asteroids with semi-major axes greater than 2.8 AU. ...
With the inception of gravitational wave astronomy, astrophysical studies using interferometric techniques have begun to probe previously unknown parts of the universe. In this work, we investigate the potential of a new interferometric experiment to study a unique group of gravitationally interacting sources within our solar system: binary asteroids. We present the first study into binary asteroid detection via gravitational signals. We identify the interferometer sensitivity necessary for detecting a population of binary asteroids in the asteroid belt. We find that the space-based gravitational wave detector LISA will have negligible ability to detect these sources as these signals will be well below the LISA noise curve. Consequently, we propose a 4.6 AU and a 1 AU arm-length interferometers specialized for binary asteroid detection, targeting frequencies between $10^{-6}$ and $10^{-4}$ Hz. Our results demonstrate that the detection of binary asteroids with space-based gravitational wave interferometers is possible though very difficult, requiring substantially improved interferometric technology over what is presently proposed for space-based missions. If that threshold can be met, an interferometer may be used to map the asteroid belt, allowing for new studies into the evolution of our solar system.
... Though some meteorites come from the Moon and Mars and it is possible that some of the least processed meteorite types (rich in carbon) originated in comets, the diversity of meteorite types is evidence for the diversity of asteroids. Some meteorite types have been linked to asteroid taxonomic classes by reflectance spectroscopy, but for many types, the link remains uncertain (DeMeo et al., 2015). ...
This chapter addresses recent developments in relation to legal regulation of space mining. More specifically, we analyze international legal regimes governing utilization of natural resources located in the areas recognized as res communis omnium, to demonstrate an important paradigm shift from the national interest-driven approach to the global interest-driven regime reflecting cosmopolitan ideas. In fact, the sharing of benefits that may be derived from the exploitation of the natural resources in areas recognized as res communis omnium represents a unique opportunity to further implement cosmopolitan ideas in international practice. Special attention is given to the regime governing deep seabed mining created by the United Nations Convention on the Law of the Sea. This regime represents the most cosmopolitan regime ever established. In the following text, we present space resources as exhaustible resources located in the area recognized as res communis omnium and analyze the most relevant principles of international space law bearing cosmopolitan ideals. The last part of the chapter looks at the recent efforts to formulate space mining legal regimes, both national and international. Since there is no universal approach to how natural resources located in the areas recognized as res communis omnium should be governed and how cosmopolitan ideas should be translated into international natural resource management, recently adopted regimes or initiatives cope with the cosmopolitan nature of outer space differently. We acknowledge that national space mining law appears to be the most effective tool to regulate space mining; however, it remains the most controversial one, unless states behave in a responsible cosmopolitan way.KeywordsSpace miningInternational lawNational space mining lawCosmopolitanismUNCLOSOuter Space TreatyMoon agreementUN COPUOSHague International Space Resources Governance Working GroupVancouver Recommendations on Space MiningInternational regime
