English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This paper studies the long-term migration of disturbed regolith materials onthe surface of Solar System small bodies from the viewpoint of nonlineardynamics. We propose an approximation model for secular mass movement, whichcombines the complex topography and irregular gravitational field. Choosingasteroid 101955 Bennu as a representative, the global change of the dynamicalenvironment is examined, which presents a division of thecreeping-sliding-shedding regions for a spun-up asteroid. In the creepingregion, the dynamical equation of disturbed regolith grains is establishedbased on the assumption of "trigger-slide" motion mode. The equilibrium points,local manifolds and large-scale trajectories of the system are calculated toclarify the dynamical characteristics of long-term regolith movement.Generally, we find for a low spin rate, the surface regolith grains flow towardthe middle latitudes from the polar/equatorial regions, which is dominated bythe gradient of the geopotential. While spun up to a high rate, regolith grainstend to migrate toward the equator, which happens in parallel with atopological shift of the local equilibria at low latitudes. From a long-termperspective, we find the equilibrium points dominate the global trends ofregolith movements. Using the methodology developed in this paper, we give aprospect or retrospect to the secular motion of regolith materials during thespin-up process, and the results reveal a significant regulatory role of theequilibria. Through a detailed look at the dynamical scheme under differentspin rates, we achieve a macro forecast of the global trends of regolith motionduring the spin-up process, which explains the global geologic evolution drivenby the long-term movements of regolith materials.

Long-term Trends of Regolith Movement on the Surface of Small Bodies