In another HiRISE picture dated October 14, astronomers showed the cross-section of a canyon system in the Valles Marineris.
The Mars picture features snaking sand dunes and ripples, also known as bedrooms.
The HiRISE team said: “Some areas display more modern bedforms, often termed mega-ripples, which have likely been active over long timescales and have migrated in the recent past.
“Other areas along the canyon wall have larger bedforms that show a very different appearance.
“Although they have a spacing that would make them similar to typical Martian sand dunes, many display superposed craters, indicating they have not migrated for a very long time, possibly hundreds of thousands of years.”
