There’s an extra, mid-month Icarus (vol. 432 15 May), stretching from submillimeter to planetary:
Whattam, S. A. Predominance of porphyritic textures in chondrules due to density sorting of precursor materials? Constraints from melting experiments Article 116510 .2025.116510
Rider-Stokes, B. G. Jackson, S. L. Burbine, T. H. et al. The mystery of the missing mantle problem and insights from spectroscopy Article 116506 .2025.116506
Slyusarev, I. G. Rychahova, V. V. Kaydash, V. G. et al. The phase- and color-ratio techniques as applied to Dawn images of the dwarf planet Ceres and asteroid (4) V…Article 116507 .2025.116507
Chondrules are some of the original building blocks of asteroids, and therefore the planets. They’re cooled droplets of once-molten minerals, generally a fraction of a millimeter to sometimes ~1 mm. Like marbles, they come in all sorts, from pure glass, to glass with an inclusion or three (generally rock crystals), to solid and opaque. What is the nature of chondrules, their origin, formation process, and history of accretion into asteroids? Whattam can replicate a lot of chondrule features in the lab.
Some asteroids accreted chondrules, and more, …and more and more, until reaching scales of hundreds of kilometers. Once a body is this size, its interior is cut off from space, and cannot shed heat. Without shedding that heat, the rocks melt; the body differentiates into a core, crust, and in between, a mantle. We have core meteorites (literal iron samples, from former cores) and crust meteorites (the achondrites), but the mantle asteroids (and the resulting meteorites) don’t add up. Where are all the mantle samples- the “missing mantle” issue? Rider-Stokes et al. claim we are overlooking a lot of asteroids (besides the A-types) that are potentially mantle chunks.
Slyusarev et al. then take a look at two such mega-asteroids. Ceres and Vesta have both been visited by a probe, and have a lot of data to test. Using the Dawn mission’s dataset, Slyusarev et al. find some interesting things about the chemistry and mineralogy of those abortive planets, and of some of their more interesting surface features.