Just up at Space Science Reviews (vol. 222):
Bierhaus, E. B. Songer, J. T. Mario, C. E. et al. Mobilization of Unconsolidated Granular Material on Asteroid (101955) Bennu by Spacecraft Interaction 33 s11214-026-01285-8
This “Special Communication” describes the use of gas pressure- both the explicit TAGSAM system, and the OSIRIS-REx maneuvering thrusters- as a way to probe asteroids (both Bennu, and Apophis in 2029). This is hardly new fodder for a research paper- just last month, Sakatani et al. asked these same questions regarding Hayabusa2 at Ryugu. And here, Bierhaus et al. cite their predecessors.
The regolith (‘dirt’) at a small, chondritic asteroid is loose particles. (Certainly so in the case of rubble-pile asteroids, those bodies re-formed from the debris of a prior, larger, impacted asteroid.) The physics and mechanics of such ‘soil’ is still a bit hazy, since we don’t have many labs with hard vacuum and microgravity. Heck, even replicating the composition was an assumption, until we returned samples. Therefore, anything that gets us regolith measurements is, literally, new ground.
After Bennu, the OSIRIS-REx spacecraft (now OSIRIS-APEX) will test the regolith at asteroid Apophis. Since the TAGSAM head is gone (any nitrogen left?), the experiment (possibly multiple shots) will be done with the spacecraft thrusters. OSIRIS-APEX will descend, then literally blow the regolith. The response of the particles will then tell us of those particles, and their particle mechanics.
Asteroid rendezvous flights (not flybys) are few and far between (and that’s with DART). We try to wring every last data point we can get out of them. This (long) paper used the spacecraft hardware, such as monitoring cameras (not the primary instruments) to prep us for asteroid surface operations.
Oh, and don’t forget to watch the appended TAGSAM video of the blast(s).