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Highlights: [•] Over 200 new, dated impact sites have been discovered on Mars. [•] We measure a current impact rate of 1.6×10−6/km2/yr for >3.9m effective diameter. [•] Resulting model ages are a factor of 5–10 below predictions based on lunar cratering. [•] Many new impacts form clusters, so D <50m craters should not be used to estimate ages. [Copyright &y& Elsevier]

The Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) imaged two newly formed impact craters on the South Polar Layered Deposits (SPLD) of Mars in 2018 and 2020. These two new craters, the first detected on the SPLD, measure ∼17 m and ∼48 m in diameter. Follow-up observations were conducted with the High Resolution Imaging Science Experiment (HiRISE), showing seasonal and interannual changes, and providing stereo coverage for the production of digital terrain models (DTMs). Mars Climate Sounder (MCS) data were obtained over the region of these new impacts, giving surface temperature information for the time interval before and after the impacts were detected. Taken together, the optical and infrared observations of these sites reveal craters largely consistent with the morphologies of other small, dated impact craters on Mars, and crater ejecta patterns that suggest a more dust/regolith-dominated upper few meters of the SPLD in contrast to mid-latitude buried ice and lobate debris aprons (LDAs). This supports previous conclusions that the SPLD may have an upper surface depleted in water ice relative to the North PLDs, possibly the result of a widespread deflation event. • 17- and 48-m diameter new (formed 2018–2020) craters were found on the South Polar Layered Deposits. • These new craters are morphologically similar to <100 m craters elsewhere on Mars. • Ejecta composition suggests the SPLD's upper meters differ from midlatitude ices. [ABSTRACT FROM AUTHOR]

The Mars Reconnaissance Orbiter has been orbiting Mars since 2006 and has acquired >80,000 HiRISE images with sub-meter resolution, contributing to over 2000 peer-reviewed publications, and has provided the data needed to enable safe surface landings in key locations by several rovers or landers. This paper describes the changes to science planning, data processing, and analysis tools since the initial Primary Science Phase in 2006–2008. These changes affect the data used or requested by the community and how they should interpret the data. There have been a variety of complications to the dataset over the years, such as gaps in monitoring due to spacecraft and instrument issues and special events like the arrival of new landers or rovers on Mars or global dust storms. The HiRISE optics have performed well except for a period when temperature uniformity was perturbed, reducing the resolution of some images. The focal plane system now has 12 rather than 14 operational detectors. The first failure (2011) was a unit at the edge of the swath width, reducing image width by 10% rather than creating a gap. The recent (2023) failure was in the middle of the swath. An unusual problem with the analog-to-digital conversion of the signal (resulting in erroneous data) has worsened over time; mitigation steps so far have preserved full-resolution imaging over all functional detectors. Soon, full-resolution imaging will be narrowed to a subset of the detectors and there will be more 2 × 2 binned data. We describe lessons received for future very high-resolution orbital imaging. We continue to invite all interested people to suggest HiRISE targets on Mars via HiWish, and to explore the easy-to-use publicly available images. • HiRISE has acquired >80,000 images of Mars with meter-scale resolution and has contributed to >2,000 publications. • HiRISE has enabled safe landings in scientifically compelling locations. • This paper describes how the experiment has changed over 14 years of extended science. • We encourage all those who are interested to suggest HiRISE targets via HiWish. [ABSTRACT FROM AUTHOR]