Sedimentary layers are stacked one atop another in this view of Danielson Crater, north of Meridiani Planum. The deposits, that cover most of the crater floor, have been deeply eroded, exposing regular layers that resemble stair steps.

Very few impact craters are observed on these layered sediments. Remarkably few small craters can be seen at HiRISE resolution. Only a pair of 750-meter diameter craters on the northeast floor of Danielson hint that these deposits could be quite ancient. Similar deposits elsewhere in this region have been estimated to date from the early Hesperian period, around 3.7 billion years ago. Why are small craters absent from sediments that are billions of years old, here in Danielson?

Most surfaces gradually accumulate craters over time, so we can count craters to estimate the ages of various geologic formations. However, the same erosion that exposes the layers may also act to erase surface features such as small craters. If erosion outpaces the rate of cratering, then an ancient deposit can appear young and crater-free. Erosion might be enhanced here by sandblasting from the dunes also trapped within Danielson Crater .

ID: ESP_089198_1885
date: 6 August 2025
altitude: 277 km

https://uahirise.org/hipod/ESP_089198_1885
NASA/JPL-Caltech/University of Arizona
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