The evolution of comet pits
Pits Ma’at 1, 2 and 3 on Comet 67P/Churyumov–Gerasimenko show differences in appearance that may reflect their history of activity. While pits 1 and 2 are active, no activity has been observed from pit 3. The young, active pits are particularly steep-sided, whereas pits without any observed activity are shallower and seem to be filled with dust. Middle-aged pits tend to exhibit boulders on their floors from mass-wasting of the sides.
The image was taken with the OSIRIS narrow-angle camera from a distance of 28 km from the comet surface. From left to right the pits measure 125 m, 130 m and 140 m across and are 65 m, 60 m and 50 m deep, respectively.
Copyright: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA