The Martian weather cake
Every layer tells a story of climate change.
The Martian ice cap is like a cake; every layer tells a story. In this case, the story is one of climate change on Mars.
This image of an exposed section of the north polar layered deposits (NPLD) looks much like a slice of layered tiramisu.
The NPLD is made up of water-ice and dust particles stacked one on top of the other. However, instead of icing, layers are topped with seasonal carbon dioxide frost, seen here as lingering frost adhering to one of the layers.
The high-resolution and colour capabilities of the Mars Reconnaissance Orbiter's HiRISE camera provides details on the variations in the layers.
Scientists are also using radar data, which show us that they have continuity in the subsurface.
During deposition, these complex layers might encapsulate tiny air pockets from the atmosphere which, if sampled, could be studied to understand linkages to previous climates.