Influence of the projectile geometry on the momentum transfer from a kinetic impactor and implications for the DART mission

Raducan, Sabina D.; Jutzi, Martin; Davison, T. M.; DeCoster, Mallory E.; Graninger, Dawn; Owen, J. Michael; Stickle, A. M.; Collins, G. S.

doi:10.1016/j.ijimpeng.2021.104147

Cited by 26 publications

(31 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For plume images obtained near or after the cone crossing, the ejection angle α does not need to be inferred simultaneously with the inference of target material cases, but an observed value of α can be used to discriminate target cases. However, at earlier times, the ejection angle may differ by 10°f rom the α value measured near or after cone crossing (Luther et al 2018;Raducan et al 2022). This variation in α should be considered to infer target physical properties.…”

Section: Discussionmentioning

confidence: 99%

“…With target cases C2 and C7, where the target strength is much larger at 30 MPa and 4 kPA, respectively, the DART impact crater would be strength-controlled and much smaller than the Dimorphos radius. The impact outcomes given in Table 3 differ slightly from those in Cheng et al (2020), because of projectile parameter updates, most importantly a larger value for the projectile radius better describing the spacecraft structure (Raducan et al 2022). Finally Table 3 shows the crater growth timescale for the three target cases, as given by point-source scaling (O'Keefe & Ahrens 1993; see Appendix B).…”

Section: Fovmentioning

confidence: 99%

See 1 more Smart Citation

Model of Double Asteroid Redirection Test Impact Ejecta Plume Observations

et al. 2022

View full text Add to dashboard Cite

The Double Asteroid Redirection Test (DART) spacecraft will impact the moon Dimorphos of the [65803] Didymos binary in order to demonstrate asteroid deflection by a kinetic impactor. DART will measure the deflection by using ground-based telescopic observations of the orbital period change of Didymos and will carry the Light Italian CubeSat for Imaging of Asteroids (LICIACube) cubesat, which will perform a flyby of Didymos about 167 s after the DART impact, obtaining images of the DART impact ejecta plume. LICIACube images showing the ejecta plume spatial structure and temporal evolution will help determine the vector momentum transfer from the DART impact. A model is developed for the impact ejecta plume optical depth, using a point-source scaling model of the DART impact. The model is applied to expected LICIACube plume images and shows how plume images enable characterization of the ejecta mass versus velocity distribution. The ejecta plume structure, as it evolves over time, is determined by the amount of ejecta that has reached a given altitude at a given time. The evolution of the plume optical depth profiles determined from LICIACube images can distinguish between strength-controlled and gravity-controlled impacts, by distinguishing the respective mass versus velocity distributions. LICIACube plume images discriminate the differences in plume structure and evolution that result from different target physical properties, mainly the strength and porosity, thereby allowing inference of these properties to improve the determination of DART impact momentum transfer.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Fovmentioning

confidence: 99%

Model of Double Asteroid Redirection Test Impact Ejecta Plume Observations

et al. 2022

View full text Add to dashboard Cite

show abstract

“…This study was motivated by the DART impact on Dimorphos; therefore, here we simulate DART-like impacts on small, Dimorphos-like targets (Naidu et al 2020). Recent studies (e.g., Owen et al 2022, this focus issue; Raducan et al 2022b) showed that a low-density spherical projectile is a reasonable approximation for a DARTlike impact. Therefore, in all simulations, we modeled the projectile as a low-density (ρ = 1000 kg m −3 ), ≈500 kg aluminum sphere at 6 km s −1 .…”

Section: Shock Physics Code Modelmentioning

confidence: 99%

“…The target was simulated using the Tillotson EoS for basalt (Benz & Asphaug 1999) with a modified initial bulk modulus (see next section). The Tillotson EoS is suitable for the impact scenarios investigated here, as only a very small proportion of the target material experiences peak shock pressures higher than the incipient or complete melting pressure (Raducan et al 2022b).…”

Section: Shock Physics Code Modelmentioning

confidence: 99%

Global-scale Reshaping and Resurfacing of Asteroids by Small-scale Impacts, with Applications to the DART and Hera Missions

Raducan

Jutzi

2022

Planet. Sci. J.

View full text Add to dashboard Cite

We use a novel approach to model the entire cratering process resulting from impacts on small, weak asteroids that uses shock physics code calculations directly. We found that small-scale impacts (with a projectile size less than 1/150 of the target size) can significantly deform weak asteroids, causing global resurfacing at the same time. As a result, the collisional lifetime of the overall asteroid shapes is significantly lower than the traditionally used lifetime based on catastrophic disruption events. We also show that even very low asteroid cohesions can drastically influence the outcome of an impact. Consequently, if the target is homogeneous and weaker than ≈10 Pa, then NASA’s Double Asteroid Redirection Test impact on Dimorphos may not lead to a cratering event, as originally anticipated. Rather, the impact may change the global morphology of the asteroid. Our results, together with future observations by the ESA’s Hera mission, will provide constraints regarding the evolution of the shapes and structures of small asteroids by subcatastrophic impacts.

show abstract

“…Many numerical simulations of the DART impact have been performed in recent years analyzing the effect of different projectile and target characteristics. (e.g., Stickle et al 2020;Raducan et al 2021Raducan et al , 2022Zhang et al 2021). Initially, for this study, the results of iSALE-2D simulations of head-on impacts of an aluminum projectile on a basalt target with an internal friction coefficient of 0.6, cohesive strength of 10 KPa, and porosity of 20% were used (provided by Raducan et al 2019).…”

Section: Initial Conditions For the Ejectamentioning

confidence: 99%

Dynamical Evolution of Ejecta from the DART Impact on Dimorphos

et al. 2022

View full text Add to dashboard Cite

The DART spacecraft will impact Dimorphos (the secondary body of the Didymos binary asteroid) to test the kinetic impactor deflection method against possibly hazardous near-Earth asteroids. The DART impact ejecta plume, and possibly the impact crater, will be imaged by the LICIACube spacecraft, hosted as a piggyback and released by DART just before the impact, and then, several years later, by the Hera probe. To exploit the wealth of data obtained and understand the physics of the whole impact experiment, it is of paramount importance to properly model the dynamics of the binary system pre- and postimpact and the dynamics of the particles ejected from the impact crater. A model was developed to simulate the evolution of the ejecta particles created during the impact in order to first interpret the LICIACube images and then test the survival of particles on long intervals of time that might be detected by the Hera mission either as individual bodies or as parts of rings. The dynamical evolution of the particles is simulated over different timescales to highlight the most important perturbations and their relative importance. The ejecta dynamics turns out to be highly chaotic due to repeated close encounters with the two asteroids. However, we find that some ejecta survive in the binary orbital environment for timescales comparable to the Hera arrival time. The effects of the particles reimpacting against either one of the components is also analyzed to estimate the amount of momentum transfer to the target bodies.

show abstract

Influence of the projectile geometry on the momentum transfer from a kinetic impactor and implications for the DART mission

Cited by 26 publications

References 38 publications

Model of Double Asteroid Redirection Test Impact Ejecta Plume Observations

Model of Double Asteroid Redirection Test Impact Ejecta Plume Observations

Global-scale Reshaping and Resurfacing of Asteroids by Small-scale Impacts, with Applications to the DART and Hera Missions

Dynamical Evolution of Ejecta from the DART Impact on Dimorphos

Contact Info

Product

Resources

About