Lines of Pits in Protonilus Mensae
HiRISE PICTURE OF THE DAY: 16 SEPTEMBER 2025
Lines of Pits in Protonilus Mensae

The objective of this observation is to examine lines of pits. Cracks (then maybe ridges and troughs) may start as lines of pits. It has been suggested that pits are caused by material collapsing into voids, after ground ice has sublimated. Studies of images like this will help us understand the evolution of surface features, the distribution of ground ice, and past climates.



HiRISE Instrument News
Since July 23, 2023, HiRISE observations have lacked data from the RED4 CCD due to a hardware issue, creating a gap in the middle of image products and reducing the color swath to 1 CCD width. We are investigating the hardware issue and may be able to acquire some RED4 data in the future.

Circular Sand Dunes
Sand dunes of many shapes and sizes are common on Mars. In this example the dunes are almost perfectly circular, which is unusual.