There’s a mid-month issue of Icarus, so let’s get caught up. In vol. 435 (15 July 2025):
Shou, Y. Combi, M. Feaga, L. et al. Surface activity of H2O and CO2 on comet 103P/Hartley2 derived from EPOXI/HRI images Article 116557 .2025.116557
Kossacki, K. J. Outgassing of ice agglomerates II Article 116541 .2025.116541
Nouzák, L. Edwards, K. Fontanese, J. et al. Laboratory measurements of the expansion characteristics of dust impact plasmas Article 116586 .2025.116586
Zhang, W-F. Wang, J-J. Zheng, D-W. et al. Correction for calcium interference in the 40Ar/39Ar dating method Article 116591 .2025.116591
Lu, Y. Zhu, M-H. Wu, Q. et al. Hypervelocity impact experiments in iron alloy targets Article 116575 .2025.116575
Deducing comet properties from imagery alone is more than a bit presumptuous… but we have images, and not much else, so presumption will happen. Here, Shou et al. claim higher-order information on Comet Hartley, from Deep Impact shots… draw your own ‘sumptions’.
Viewing from the other end of the “shot”- some comet activity is tiered. Some comets eject clumps, then those clumps emit dust and volatiles. Those clumps can be thought of as ‘micro comets’, and the (macro) comet is then called “hyperactive” (additional surface area for emissions). Kossacki et al. describe those clumps, that we may better understand (macro) comets and their activity.
The other end of comet activity, then, is the demise of the emitted dust, as meteors or as impactors. For the case of impactors, Nouzák et al. consider the ‘fireballs’ from such dusts.
Both comets and asteroids hold volatiles. In the case of argon, that element can be produced by multiple pathways. Gauging the relative amounts of two Ar isotopes (from two paths) is a way to find the age of that small body. Zhang et al. consider higher-order effects on that age value.
Psyche (the probe) is getting closer to Psyche (the asteroid). In the lead-up to new discoveries to be found, Lu et al. try experimental astronomy. Using Psyche-relevant alloys, they simulate meteorite bombardment in the lab. Do craters in iron turn out different from prior (rock) craters?