SEEING VENUS TESSERA TERRAIN WITH THE VENDI CAMERA ON DAVINCI (Invited Presentation)

The Deep Atmosphere Venus Investigation of Noble Gases, Chemistry and Imaging (DAVINCI) mission was recently selected as one of two missions to explore Venus under NASA’s Discovery mission program. DAVINCI will deploy an instrumented probe to measure gas species during descent to the Venus surface. The Venus Descent Imager (VenDI) is a two-channel NIR camera built by Malin Space Science Systems that will allow unprecedented imaging of the Venus surface from ~ 35 km altitude to the surface, providing multiple images with sub-meter resolution. The capability drove the selection of the DAVINCI entry-descent corridor site, to allow descent imaging over the tessera terrain of Alpha Regio. Tessera terrain is the stratigraphically oldest material on the Venus surface which has an average crater age of ca. 1 Ga. The ubiquitous folds and faults of their surface record an extinct geodynamic regime of higher strain rates and thermal gradient then at present. While the volcanic plains that cover the majority (~80%) of the surface are thought to be basaltic by extrapolation from lander measurements, the composition of the tesserae has not yet been measured directly. However, orbital NIR imaging of the tesserae, including Alpha Regio, from prior missions indicates that they may be comprised of silicic rocks. The production of copious amounts of silicic rocks would indicate a formation during a prior era when water-rich rocks could be recycled into the mantle to permit magmatic differentiation. DAVINCI will deliver VenDI below the clouds that obscure the surface from orbit and will collect images at VNIR wavelengths and at much higher resolution than achievable from orbit (200 m down to sub-meter), providing a critical constraint on NIR emissivity and SAR measurements from orbit both in hand, and those collected by the VERITAS orbiter expected to be at Venus concurrently. The VenDI data will also allow the production of high-resolution digital elevation models to aid in the assessment of the km-meter scale morphology, structure, depositional and erosional processes in tessera terrain at spatial scales not possible from orbit. These data will also critically enable future landed missions to perhaps the oldest accessible rocks on Venus.