Presentation #104.01 in the session “Bennu and Ryugu: The Sun and the Sea”.
Remote sensing observations of asteroids, via reflectance spectroscopy, has been an effective way to classify, as well as characterize, the surfaces of these airless bodies. One key characteristic that has proven useful in the near-infrared region is the spectral slope. In many cases, an observed red spectral slope is believed to be caused by the presence of chemically reduced (metallic) iron, which has been hypothesized to be formed via space weathering processes, such as solar wind and micrometeorite impacts. However, although it seems like all asteroids should be subject to some form of space weathering, not all asteroids exhibit a red slope. In fact, some asteroids, such as Bennu, clearly show a blue slope in the near-infrared spectral region. Whether this blue spectral slope could also be indicative of space weathering, a lack of space weathering or some other surface characteristic/process is not currently understood. Here we present some of our more recent laboratory results that investigate possible origins of a blue spectral slope on airless bodies, such as Bennu.