Browsing by Author "Jones, Rhian H."

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    CASTAway: An asteroid main belt tour and survey
    (Elsevier, 2017-11-01) Bowles, Neil E.; Snodgrass, Colin; Gibbings, Alison; Sanchez, Joan-Pau; Arnold, Jessica A.; Eccleston, Paul; Andert, Tom; Probst, A.; Naletto, Giampiero; Vandaele, A. C.; de Leon, J.; Nathues, A.; Thomas, Ian R.; Thomas, Nicholas; Jorda, Laurent; Da Deppo, Vania; Haack, H.; Green, Simon F.; Carry, Benoit; Donaldson Hanna, Kerri L.; Leif Jorgensen, J.; Kereszturi, Akos; DeMeo, F. E.; Patel, Manish R.; Davies, John K.; Clarke, Fraser; Kinch, K.; Guilbert-Lepoutre, A.; Agarwal, J.; Rivkin, Andy S.; Pravec, Petr; Fornasier, Sonia; Granvik, Mikael; Jones, Rhian H.; Murdoch, Naomi; Joy, Katherine H.; Pascale, Enzo; Tecza, Matthias; Barnes, Jenny M.; Licandro, J.; Greenhagen, Benjamin T.; Calcutt, Simon B.; Marriner, C. M.; Warren, Tristram; Tosh, Ian
    CASTAway is a mission concept to explore our Solar System’s main asteroid belt. Asteroids and comets provide a window into the formation and evolution of our Solar System and the composition of these objects can be inferred from space-based remote sensing using spectroscopic techniques. Variations in composition across the asteroid populations provide a tracer for the dynamical evolution of the Solar System. The mission combines a long-range (point source) telescopic survey of over 10,000 objects, targeted close encounters with 10–20 asteroids and serendipitous searches to constrain the distribution of smaller (e.g. 10 m) size objects into a single concept. With a carefully targeted trajectory that loops through the asteroid belt, CASTAway would provide a comprehensive survey of the main belt at multiple scales. The scientific payload comprises a 50 cm diameter telescope that includes an integrated low-resolution (R = 30–100) spectrometer and visible context imager, a thermal (e.g. 6–16 µm) imager for use during the flybys, and modified star tracker cameras to detect small (∼10 m) asteroids. The CASTAway spacecraft and payload have high levels of technology readiness and are designed to fit within the programmatic and cost caps for a European Space Agency medium class mission, while delivering a significant increase in knowledge of our Solar System.
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    The Winchcombe meteorite: a regolith breccia from a rubble pile CM chondrite asteroid
    (Wiley, 2022-12-21) Suttle, Martin D.; Daly, Luke; Jones, Rhian H.; Jenkins, L.; van Ginneken, Matthias; Mitchell, Jennifer T.; Bridges, J. C.; Hicks, L. J.; Johnson, Diane
    The Winchcombe meteorite is a CM chondrite breccia composed of eight distinct lithological units plus a cataclastic matrix. The degree of aqueous alteration varies between intensely altered CM2.0 and moderately altered CM2.6. Although no lithology dominates, three heavily altered rock types (CM2.1–2.3) represent >70 area%. Tochilinite–cronstedtite intergrowths (TCIs) are common in several lithologies. Their compositions can vary significantly, even within a single lithology, which can prevent a clear assessment of alteration extent if only TCI composition is considered. We suggest that this is due to early alteration under localized geochemical microenvironments creating a diversity of compositions and because later reprocessing was incomplete, leaving a record of the parent body's fluid history. In Winchcombe, the fragments of primary accretionary rock are held within a cataclastic matrix (~15 area%). This material is impact-derived fallback debris. Its grain size and texture suggest that the disruption of the original parent asteroid responded by intergranular fracture at grain sizes <100 μm, while larger phases, such as whole chondrules, splintered apart. Re-accretion formed a poorly lithified body. During atmospheric entry, the Winchcombe meteoroid broke apart with new fractures preferentially cutting through the weaker cataclastic matrix and separating the breccia into its component clasts. The strength of the cataclastic matrix imparts a control on the survival of CM chondrite meteoroids. Winchcombe's unweathered state and diversity of lithologies make it an ideal sample for exploring the geological history of the CM chondrite group.