Gullies on the Northern Crater Slope in Terra Sirenum
HiRISE PICTURE OF THE DAY: 22 APRIL 2025
Gullies on the Northern Crater Slope in Terra Sirenum

These gullies start at or below the crater rim and are relatively large, with broad source alcoves and inner channels that continue down onto the gullies’ aprons.



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.