Seasonal southern circum-polar spots and araneiforms observed with the colour and stereo surface imaging system (CaSSIS)

The southern polar area of Mars is home to various seasonal activity commonly explained by the Kieffer model. During spring, ice covering sublimates and leaves distinct features (spiders, spots, fans) observable from orbit. Colour Stereo Surface Imaging System (CaSSIS) onboard ExoMars Trace Gas Orbiter (TGO), provides high-resolution multi-filter images Martian surface offering high sensitivity colour contrasts. Its stereo capability pivotal for momentary processes offers a unique perspective studying sublimation their relation atmospheric features. For first time, we identify clouds well correlated with (araneiforms spots at circum-polar latitudes) hence motivating new campaign refine these observations over time periods where CO2 occur. We focus here on structure spot deposits evolution through time. describe seven structures: dark spot, bright-haloed ringed inverted dark-haloed banded bright spot. By morphological spectral analyses, hypothesize chronology events that characterise origin, formation