CAB Seminar on Thursday 26th of March at 12:00 (CET) by Jens Örmo (CAB)

[Laura Colzi]

 

 

 

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CAB SEMINARS

Pounding imparts internal strength to rubble-piles

 

Jens Örmo (CAB)

Thursday, 26th March 2026, 12:00 (CET) (Auditorio/Zoom)

It is known that nearly all 0.2-10 km, thus frequent, asteroids are "rubble-piles". However, their internal structure remains largely uncertain, but a strength-stratification with a weaker exterior compared with the interior has been suggested for e.g., Bennu. We use projectile impact experiments to explore a possible formation mechanism for this strength stratification. High-speed video recordings show that material from crushed target boulders and projectile rapidly penetrates radially beneath the floor of the expanding cavity in porous target. Similar features are known from terrestrial impact structures where it penetrates fractures opening in the basement. On a rubble-pile asteroid, repeated impacts over time in a porous and easily crushable material could lead to accumulation of fine-grained, and increasingly compacted and cohesive material at depth. Meanwhile, impact-induced seismic activity on the asteroid, causing granular convection, along with rotational centrifugal forces, could promote the segregation of finer material beneath coarser layers, potentially making this effect more pronounced at the poles.

 

Join zoom meeting at: https://rediris.zoom.us/j/85134397594?pwd=Sms4OUdSWmdocGh3R1dwU1NJaWk2Zz09

Meeting ID: 851 3439 7594
Passcode: 125143

Previous seminars can be found at CAB YouTube channel: https://www.youtube.com/c/CentrodeAstrobiologia

 

A full list of seminars in our webpage: https://cab.inta-csic.es/en/training/academy/cab-seminars-2025-2026/

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