LPSC Meeting 2024, part 2

…to continue, a big push at LPSC was space weathering, of both Ryugu and Bennu.

-Both Ryugu and Bennu grains show some palpably space-weathered surfaces, presumably the outward sides of exposed (surface) regolith particles. The space weathering is palpable as “froth”, at least, as frothy as solid rock gets. Rock, heated by the energy of microimpacts/solar ion bombardment, has its volatiles mobilized and vaporized. This escaping gas (plasma?) then froths the heated rock. We are now seeing the re-frozen porosities.

-Where Hayabusa studied a stony (S-complex) asteroid, Haya2 and OREx went to C-complex (carbonaceous chondrite) bodies. Now we have context: where the water and other volatiles on Itokawa were low, Ryugu/Bennu have water/hydroxyl, sulfur compounds, phosphates, carbonates/organics, possibly ammoniated compounds. And the work continues; we have some initial noble gas results.

-This has implications for telescopic studies, and therefore asteroids in general. With weathering effects now observed, we can draw better inferences on, oh- every other asteroid, S- or C-, seen in telescopes, with a clue towards possible surface modification and alteration due to weathering. And since C-complex bodies span comet nuclei as well, we could add Rosetta data as another piece of the puzzle.

Onward and upward!