Ovda Fluctus (6.1°S, 95.5°E) is a lava flow complex on the equatorial tessera highlands of Ovda Regio, Venus. We examined its morphology and geologic setting to determine if its apparent emplacement rheology is consistent with silica‐rich (e.g., rhyolitic) lava; this has significant implications for the compositions of Venus's tesserae. Using Magellan radar data, we find that the radar properties (emissivity, roughness, and backscatter) of Ovda Fluctus are similar to those of the surrounding tessera, although the flow is smoother at multiple scales. Ovda Fluctus is a “festoon flow complex,” whose surface is rumpled into arcuate folds. The flow includes multiple flow lobes and at least two distinct flow units. The flow complex includes a portion at high altitude (~5 km above mean planetary radius) that has low radar backscatter and high radar emissivity compared with lower‐altitude portions of the complex. The high‐altitude region of Ovda Fluctus is continuous with the lower‐elevation portions: the change in radar properties does not represent different flows. Outlines of Ovda Fluctus flow lobes have fractal dimensions consistent with basaltic pahoehoe lavas. The margin of Ovda Fluctus is at significantly higher elevation than its center, a characteristic seen in basalt flows on Earth, but not on more silica‐rich flows. Thus, the available evidence suggests that Ovda Fluctus had an emplacement rheology consistent with a basaltic composition; this result provides no support for hypotheses that Ovda Regio (a highlands tessera terrain) is composed of granitic rock.

The NASA Artemis program will send humans to the lunar south polar region, in part to investigate the availability of water ice and other in situ resources. While trace amounts of ice have been detected at the surface of polar permanently shadowed regions (PSRs), recent studies suggest that large ice deposits could be stable below cold traps in the PSRs over geologic time. A recent study modeling the rate of ice delivery, ejecta deposition and ice loss from cold traps predicted that gigatons of ice could be buried below 100s of meters of crater ejecta and regolith. However, crater ejecta vigorously mix the target on impact through ballistic sedimentation, which may disrupt buried ice deposits. Here, we developed a thermal model to predict ice stability during ballistic sedimentation events. We then modeled cold trap ice and ejecta stratigraphy over geologic time using Monte Carlo methods. We found that ballistic sedimentation disrupted large ice deposits in most cases, dispersing them into smaller layers. Ice retention decreased in most cases, but varied significantly with the sequence of ejecta delivery, particularly from basin‐forming events. Over many model runs, we found that south polar craters Amundsen, Cabeus, and Cabeus B were most likely to retain large deposits of ice at depths up to 100 m, shallow enough to be detectable with ground‐penetrating radar. We discuss these findings in the context of the imminent human exploration activities at the lunar south pole.