As much as there are ‘monthly issues’ for Monthly Notices of the Royal Astronomical Society, here are the ‘issue(s)’ for December:
Volume 535, #2, December 2024
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Volume 535, #3, December 2024
Chen, Yue Li, Jian A new multiple-arc model of the resonant Kuiper belt objects – Plutinos
Pages 2291–305, stae2462
Liu, Mu-Lin et al. Stability of spatial orbits around Earth–Moon triangular libration points
Pages 2619–632, stae2399
Volume 535, #4, December 2024
Gherase, R. M. et al. The physical properties of two potential targets for space missions: (155140) 2005 UD and (612267) 2001 SG286 Pages 3077–087, stae2460
Medeiros, H. et al. Physical properties of five near-Earth asteroids within the NEOROCKS project
Pages 3479–488, stae2332
Ďurišová, S. et al. Parent comets of IAU MDC meteoroid streams unaltered by dynamical evolution
Pages 3661–685, stae2547
Issue #3 is about celestial mechanics- how, using gravity, do we know the orbits of objects, including tracing backwards and predicting forwards? Long-term, is a given orbit very stable, or just quasi-stable (implying some origin, backwards, and a fate, forwards)?
The last issue given as “December” goes a little deeper. 2005 UD is an interesting object, meriting consideration- it’s in a family with (3200) Phaethon (meaning they’re likely fragments of a parent body). Like Phaethon, 2005 UD has been observed weakly emitting matter, making it an active asteroid/dark comet/whatever, something. And also like Phaethon, it is in an Earth-crossing orbit, making it accessible, at least for a flyby. (A rendezvous, now that’s costly, in terms of propellant and mass and launch cost.) On the other hand, 2001 SG286 is in a quite accessible orbit, with low ΔV. A mission to 2001 SG286 would be (in space terms) easy.
And that’s the point of the NEOROCKS program. NEOROCKS is a European effort to better characterize Near-Earth Objects, beyond being just a dot in the sky. Too many of them are just dots, because we’ve invested the money (mostly) needed for search telescopes. Follow-up telescopes, not so much. The backlog of interesting objects- for mining, for science, or just for their impact potential and risk- is large, and growing.
Ďurišová et al. take the problem backwards. If we see meteoroids in Earth’s atmosphere- enough meteoroids to form a shower, and not just coincidentally close- where did that shower come from? Meteoroids taking common paths imply they were in a ‘family’ from a parent comet (or active asteroid, like Phaethon). How well can we trace a meteor shower back to some parent object? No, we haven’t completely solved this issue yet. For one, there are lots of lesser meteor showers in the sky.