The current issue (vol. 76 #5, Oct) of Publications of the Astronomical Society of Japan includes:
Homma, K. A. Okuzumi, S. Arakawa, S. et al. Isotopic variation of non-carbonaceous meteorites c… p. 881 psae052
Arimatsu, K. Yoshida, F. Hayamizu, T, et al. Diffraction modeling of a 2023 March 5 stellar occultation by subkilometer-sized asteroid (98943) 2001 CC21 p. 940 /psae060
First, there was planetary migration: the acceptance that planets were not pristine, immovable bodies, but can actually shift. We needed this to explain “Hot Jupiters”- exoplanet systems with no resemblance to ours. Then came the Nice Model, and Improved Nice Model. Accepting that planets can move orbits, it appears Jupiter, Saturn, etc. had moved, which explains a lot about our Solar System. It (mostly) explains carbonaceous chondrite meteorites, and their presumed parents, the carbonaceous (C-complex) asteroids. Now, Homma et al. want to keep explaining. The details of the early Solar System and its shifts do not stop material from skipping across Jupiter, it seems.
K. Arimatsu is seen in papers, participating in asteroid missions. After dropping off its Ryugu samples, the Hayabusa2 main craft is on an extended mission, including to asteroid (98943), now named Torifune. What can we learn, to prepare for Haya2’s flyby? Arimatsu et al. did not just see an occultation- Torifune blocking out the light of a background star, as it passes across. They also saw higher-order optical effects: the diffraction of that star’s light as it skims the edges (“limb”) of Torifune. This extra data seems (there are upper and lower limits) to tell us more.
Asteroids are the preserved evidence of the Solar System’s history. We have smart people working in this field for a reason: we are pursuing the Solar System’s history… our history.