HiPOD Monday, 14 Jun 2021: A Martian Dust Avalanche
Relatively dark slope streaks are common on steep dust-mantled slopes of Mars. When imaged under high sun illumination they appear to be just a dark stain without topographic relief.
However, when imaged with the sun low in the sky (and at high resolution), we can clearly see the topographic signature.
@HiRISE
What's more interesting is the scale of spread relative to the initial points/source of the avalanches. The ones at 3:00 and 4:00 is mere points that seem to cascade into much larger flows. Some look like meteor craters! Unstable ground layers below? Hard to see all of that material cleanly emanated from those points unless it was a low-flow geyser on an angle.