This image shows us great examples of transitioning streaks in Arabia Terra.
One streak is very dark and probably fresh, likely caused by a falling boulder that succumbed to gravity and rolled downhill. But in other parts of our image, we can see former streaks that have completely faded away.
ID: ESP_065261_1935
date: 28 June 2020
altitude: 277 km
https://uahirise.org/hipod/ESP_065261_1935
NASA/JPL/UArizona
