There’s a mid-month issue of Icarus, for 15 Sep (vol. 438):
Jedicke, R. Alessi, E. M. Wiedner, N. et al. The steady state population of Earth’s minimoons of lunar provenance Art. 116587 .2025.116587
Combi, M. R. Mäkinen, T. Bertaux, J.-L. et al. Water production rates from SOHO/SWAN observations of Comets C/2017 K2 (PanSTARRS) and C/2022 E3 (ZTF) Art. 116645 .2025.116645
Li, Z. Chowdhury, Y. A. Ivezić, Ž. et al. Estimates of rotation periods for Jupiter Trojans with the Zwicky Transient Facility photometric lightcurves Art. 116609 .2025.116609
We have now observed multiple mini-moons (temporarily-captured orbiters). However, based on spectra, some claim that the captured asteroids are actually lunar ejecta, thrown out by major impacts and sent into a heliocentric orbit. Based on the finite ejection energy, that heliocentric orbit is still relatively close to Earth. That close orbit, then, makes these ejected boulders vulnerable to (eventual) recapture by Earth’s gravity. Or that’s how the story goes; how likely is that story? The fact that one can craft a plausible tale does not actually make that tale plausible. Here’s science in action: testing the tale. Jedicke, long a researcher of mini-moons, and his coauthors decided to evalute- rigorously, with numbers- the likelihood of these captured objects being ‘real’ asteroids, versus lunar ejecta.
And now we revisit an old topic: comet activity. The Rosetta mission failed to deduce the processes that result in comet emission of volatiles (plus any solids entrained in the escaping gases). And even if it had, we would still look to other comets, tracking their production rates, to enumerate their volatile inventories and warmup/cooldown stages. The interesting thing about Combi et al. is that they used SOHO- a solar-observing space mission- to view comets as they continue heading inward from Earth, difficult or impossible to do with ground telescopes. In other words, more stages and volatiles data.
Looking a bit to the future, Jupiter Trojans will be studied by the Lucy mission. Before it gets to its targets, we’d like to prevent any surprises that might disrupt the program. More likely and less dramatic, we can study other Trojans besides the Lucy flyby objects, for wider context. Li et al. study multiple Trojans. The (ZTF) Zwicky Transient Facility sweeps the night sky, using a wide-field telescope. In the course of this sky survey, it coincidentally catches asteroids and comets, including asteroid-comets. Li et al. then combed through the ZTF dataset to cull the Jupiter Trojans they wanted, at multiple times.