The asteroid 4 Vesta is different from most other asteroids because Earth-based telescopic spectroscopy suggests that it has a basaltic to ultramafic composition (McCord et al., 1970; Binzel et al., 1997; Gaffey, 1997; Thomas et al., 1997a). This composition matches very closely to that of the howardite-eucrite-diogenite (HED) meteorites, as determined from laboratory studies. This compositional similarity, along with the recognition of a) dynamical considerations connecting the vestoids of the Vesta family to Vesta (Binzel and Zu, 1993; Binzel et al., 1999), b) resonances indicating Vesta can be the launching point for meteorites from large impacts (Zappala et al., 1995; Marzari et al., 1996; Asphaug, 1997), and c) cosmic-ray exposure ages of the HED meteorites (Eugster and Michel, 1995; Welton et al., 1997) all suggest that Vesta is the parent body for the HED meteorites. The meteorites isotopic compositions and spectroscopy (along with the discovery by the Hubble Space Telescope of a ~460 km diameter impact crater near the Vesta south pole, which exposed the interior of the asteroid: Thomas et al., 1997a) further suggest that Vesta is a differentiated body with a basaltic crust and ultramafic mantle, and that differentiation occurred in the first 10 Ma of solar system history. Thus, Vesta is of great interest for understanding the earliest differentiation in small bodies at the dawn of the solar system (Keil, 2002, p. 573). In particular, the hypothesis based on asteroid spectroscopy and meteorite textural and compositional studies that basaltic lava flows extruded onto the surface of Vesta (e.g., Wilson and Keil, 1996) so early in solar system history suggests that Vesta is the ideal object to study the remnants of some of the earliest volcanic eruptions in the Solar System. NASA launched the Dawn spacecraft to orbit and explore Vesta from August 2011 through May 2012. Among the Dawn at Vesta science objectives are to determine the origin and evolution of Vesta and to identify, map, and characterize geological and cratering processes and their chronology. I, David A. Williams, wish to join the Dawn mission as a Participating Scientist: 1) to conduct a science investigation using Framing Camera (FC) images to test the hypothesis of ancient volcanism on Vesta by identifying, characterizing, and mapping any and all igneous deposits on the surface of Vesta, and comparing observed features to those predicted by previous mathematical modeling (Wilson and Keil, 1996, 1997), drawing on my experience as a planetary volcanologist who has studied such features on other airless bodies such as the Moon and Io; and 2) to provide operational support for the FC instrument team in high-resolution target planning, image processing, data analysis, and data validation and archiving, drawing on my experience as a member of the NASA Galileo Solid-State Imaging (SSI) and the ESA Mars Express (MEX) High-Resolution Stereo Camera (HRSC) teams. The proposed investigation, which has both scientific and operational components, also includes funding for a graduate student to help train the next generation of planetary scientists, as encouraged by the Dawn Science Team
|Effective start/end date||8/10/10 → 12/31/14|
- NASA: Goddard Space Flight Center: $260,000.00
Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.