Understanding the evolution of asteroidal surfaces caused by impacts using numerical simulation for granular particles.

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540459
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Chiba Institute of Technology
• Principal Investigator: WADA Koji 千葉工業大学, 惑星探査研究センター, 上席研究員 (10396856)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 天体衝突 / 数値シミュレーション / 粉体 / 小惑星

Outline of Final Research Achievements

The surfaces of asteroids and planetesimals are highly porous granular layers under small gravity. We conducted numerical simulations of impacts onto such layers using a numerical code, so-called Distinct Element Method in order to evaluate influences of celestial body impacts on the evolution of asteroids and planetesimals. Our results show that a projectile in penetrating granular layer is affected by a drag force consisting of an inertia term and a viscous term and that the total amount of ejecta mass at impact is proportional to the projectile momentum. These results allow us to quantitatively discuss on the evolution of asteroidal surfaces which is determined by the balance between addition and erosion of impact bodies.

Free Research Field

天体衝突現象をはじめとする惑星科学