Linear grooves such as these are common on the martian moon Phobos. These grooves are 200–300 meters across, up to 30 meters deep, and up to 20 kilometers long. In some cases, these grooves are actually a series of aligned pits that form a chain. The grooves may result from fractures within Phobos created during the formation of the 10-kilometer-diameter crater Stickney, located just off the left edge of the image. The wide grooves may have formed when regolith and soil drained into these fractures.
1 images 343A15, 343A29.