Up in Planetary and Space Science for Feb (vol. 271):
Garciá, L. N. Macchi, J. A. Shen, P. et al. Evidence of co-temporality between olivine and metal in Tucson Art 106241 .2026.106241
Pires, P. Synchronous spin-orbit resonances in earth co-orbital asteroids: A study using parametric and real-ephemeris models Art 106243 .2026.106243
That Tucson meteorite is a weird one. While we certainly have found iron meteorites, Tucson is unlike any other we’ve found and catalogued, ever- instead of a meteorite group, we have “Iron- ungrouped.” The Tucson meteorite is iron alloy, with small inclusions of sillicate and other stony minerals, yet it’s not a Pallasite- the usual suspect for such mixtures. Nor does it match the mesosiderites.
Garciá et al., in deducing a history of Tucson from tracer elements, find some unusual history suggested. Rather than melt inclusions, collisional fragments, etc., they find that the iron and the minerals appear to date from the same time. Quite unusual if true.
Also a matter of time: do the small bodies trapped by Earth’s gravitational influence share some common origin? Once a space body is spinning, it wants to keep spinning, unless something accelerates or decelerates it. With no air, bodies in space are enormous gyroscopes. If multiple asteroids in the same region share common (or similar but opposed) spin vectors, that’s a sign that they’re actually a family- the pieces split apart by a collision on some parent asteroid. Pires gives the theory a whirl.