Spin-up of rubble-pile asteroids: Disruption, satellite formation, and equilibrium shapes

Walsh, K. J.; Richardson, D. C.; Michel, Patrick

doi:10.1016/j.icarus.2012.04.029

Cited by 128 publications

(132 citation statements)

References 51 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…In the first scenario, material flows occur globally, causing the formation of a uniform equatorial ridge. This scenario corresponds to the result by obtained Walsh et al (2008Walsh et al ( , 2012. In the second scenario, a local deformation leads to further structural bias, causing the further emergence of local material flows.…”

Section: Discussionsupporting

confidence: 82%

“…Finally, we compare the HSDEM by Walsh et al (2008Walsh et al ( , 2012 with our model. Walsh et al (2008Walsh et al ( , 2012 observed surface shedding from a rubble pile body with a homogeneous hexagonal closed packing (HCP) structure 4 , while we concluded that a body should have an internal core to have surface shedding.…”

Section: Discussionmentioning

confidence: 99%

“…Guibout & Scheeres (2003) investigated the surface stability due to the shape and spin period of a uniformly rotating, self-gravitating ellipsoid and found that based on the body configuration, the surface materials may accumulate at different ends. Using a Hard-Sphere Discrete Element Method (HSDEM), Walsh et al (2008Walsh et al ( , 2012 showed the formation of a binary system due to mass ejection from a cohesionless spheroid. By considering a constant angle of repose, Minton (2008) and Harris et al (2009) numerically obtained equilibrium shapes of a uniformly rotating symmetric body and obtained a body shape similar to 1999 KW4 Alpha.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Internal Structure of Asteroids Having Surface Shedding Due to Rotational Instability

Hirabayashi

Sánchez

Scheeres

2015

ApJ

View full text Add to dashboard Cite

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to such surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-Sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong enough core in a progenitor body, surface shedding is the most likely failure mode.

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Internal Structure of Asteroids Having Surface Shedding Due to Rotational Instability

Hirabayashi

Sánchez

Scheeres

2015

ApJ

View full text Add to dashboard Cite

show abstract

“…In agreement with literature results on the asteroid rotational properties, the fastest rotators (P rot  5 hr) tend to acquire more spheroidal shapes with increasing spin rates, due to mass loss that can eventually lead to binary asteroid formation (e.g., Walsh et al 2012).…”

Section: Taxonomy Versus Rotational Propertiessupporting

confidence: 91%

Grasping the Nature of Potentially Hazardous Asteroids

Perna

Dotto

Ieva

et al. 2015

View full text Add to dashboard Cite

Through their delivery of water and organics, near-Earth objects (NEOs) played an important role in the emergence of life on our planet. However, they also pose a hazard to the Earth, as asteroid impacts could significantly affect our civilization. Potentially hazardous asteroids (PHAs) are those that, in principle, could possibly impact the Earth within the next century, producing major damage. About 1600 PHAs are currently known, from an estimated population of 4700±1450. However, a comprehensive characterization of the PHA physical properties is still missing. Here we present spectroscopic observations of 14 PHAs, which we have used to derive their taxonomy, meteorite analogs, and mineralogy. Combining our results with the literature, we investigated how PHAs are distributed as a function of their dynamical and physical properties. In general, the "carbonaceous" PHAs seem to be particularly threatening, because of their high porosity (limiting the effectiveness of the main deflection techniques that could be used in space) and low inclination and minimum orbit intersection distance (MOID) with the Earth (favoring more frequent close approaches). V-type PHAs also present low MOID values, which can produce frequent close approaches (as confirmed by the recent discovery of a limited space weathering on their surfaces). We also identified those specific objects that deserve particular attention because of their extreme rotational properties, internal strength, or possible cometary nature. For PHAs and NEOs in general, we identified a possible anti-correlation between the elongation and the rotational period, in the range of P rot ≈5-80 hr. This would be compatible with the behavior of gravity-dominated aggregates in rotational equilibrium. For periods 80-90 hr, such a trend stops, possibly under the influence of the YORP effect and collisions. However, the statistics is very low, and further observational and theoretical work is required to characterize such slow rotators.

show abstract

“…These properties include the oblate spheroidal shape of the primary, the size ratio of the primary to the secondary, and the circular equatorial secondary orbit. Mass shedding from the primary has been shown to reproduce those properties (Walsh et al, 2008(Walsh et al, , 2012, giving constraints to the internal structure of the progenitor. Other fission scenarios have been proposed that imply different physical properties of the binary and its progenitor (Jacobson and Scheeres, 2011).…”

Section: Scientific Motivationsmentioning

confidence: 97%

Science case for the Asteroid Impact Mission (AIM): A component of the Asteroid Impact & Deflection Assessment (AIDA) mission

Michel

Cheng

Küppers

et al. 2016

Advances in Space Research

Self Cite

104

View full text Add to dashboard Cite

The Asteroid Impact & Deflection Assessment (AIDA) mission is a joint cooperation between European and US space agencies that consists of two separate and independent spacecraft that will be launched to a binary asteroid system, the near-Earth asteroid Didymos, to test the kinetic impactor technique to deflect an asteroid. The European Asteroid Impact Mission (AIM) is set to rendezvous with the asteroid system to fully characterise the smaller of the two binary components a few months prior to the impact by the US Double Asteroid Redirection Test (DART) spacecraft. AIM is a unique mission as it will be the first time that a spacecraft will investigate the surface, subsurface, and internal properties of a small binary near-Earth asteroid. In addition it will perform various important technology demonstrations that can serve other space missions.The knowledge obtained by this mission will have great implications for our understanding of the history of the Solar System. Having direct information on the surface and internal properties of small asteroids will allow us to understand how the vaious processes they undergo work and transform these small bodies as well as, for this particular case, how a binary system forms. Making these measurements from up close and comparing them with ground-based data from telescopes will also allow us to calibrate remote observations and improve our data interpretation of other systems. With DART, thanks to the characterization of the target by AIM, the mission will be the first fully documented impact experiment at asteroid scale, which will include the characterization of the target's properties and the outcome of the impact. AIDA will thus offer a great opportunity to test and refine our understanding and models at the actual scale of an asteroid, and to check whether the current extrapolations of material strength from laboratory-scale targets to the scale of AIDA's target are valid. Moreover, it will offer a first check of the validity of the kinetic impactor concept to deflect a small body and lead to improved efficiency for future kinetic impactor designs. This paper focuses on the science return of AIM, the current knowledge of its target from ground-based observations, and the instrumentation planned to get the necessary data.

show abstract

Spin-up of rubble-pile asteroids: Disruption, satellite formation, and equilibrium shapes

Cited by 128 publications

References 51 publications

Internal Structure of Asteroids Having Surface Shedding Due to Rotational Instability

Internal Structure of Asteroids Having Surface Shedding Due to Rotational Instability

Grasping the Nature of Potentially Hazardous Asteroids

Science case for the Asteroid Impact Mission (AIM): A component of the Asteroid Impact & Deflection Assessment (AIDA) mission

Contact Info

Product

Resources

About