| Popis: |
Space weathering on primitive asteroids is an ongoing area of research. Primitive asteroids have low geometric albedo (= 0.15) and mostly featureless visible spectra (~0.5 - 0.9 µm) (Campins et al. 2018). Higher albedo S-type asteroids and their corresponding meteorites, ordinary chondrites, have well-characterized space weathering effects. The generally lower albedo primitive asteroids and their less common corresponding meteorites, carbonaceous chondrites, have shown various, sometimes disagreeing results in laboratory simulations. Experiments simulating solar wind exposure on carbonaceous chondrites by Lantz et al. (2017) and Nakamura et al. 2019 showed complex trends on different types of meteorite samples. Thompson et al. (2019) simulated micrometeorite impacts on CM meteorites. Results from the Japanese sample return mission Hayabusa2 to asteroid Ryugu show an agreement with trends found by both Thompson et al. (2019) and Nakamura et al. (2019). Here, I investigate various laboratory simulations of carbonaceous chondrites to determine if certain experimental conditions were leading to disagree- ing results. The two main differences I analyzed were the preparation of the sample (powder or pellet or chip) and type of space weathering being simulated (solar wind or micrometeorite bombardment). My analysis shows no clear trend for these space weathering results, suggesting the experiments on carbonaceous chondrites may not be accurately representing what is happening to their primitive asteroid counterparts. |
