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Aeolian landforms are widespread in our solar system. Understanding the exact nature and processes of formation of these features are challenging tasks necessitating a strong collaboration between scientists with different skills and scientific backgrounds. This paper describes the special issue for the 5th International Planetary Dunes Workshop, which includes 15 research papers and three commentaries. Among the 18 papers included in this collection, 16 cover Martian aeolian science and two Titan aeolian science. The papers presented focus on bedform morphology and dynamics via remote sensing data, modeling, analogs studies and laboratory experiments. Here we put the main results of the papers in their appropriate scientific context and discuss potential future lines of research. Plain Language Summary: Wind‐sculpted (aeolian) landforms are found on many bodies of our solar system. Their study is fundamental to understanding the geology and climate of these bodies and to safely plan extraterrestrial missions. Here we introduce a collection of papers describing aeolian features on Mars and Titan. Collectively, the papers presented in this special issue show the importance of an interdisciplinary approach in comprehending what we are seeing on other planets. The study of wind landforms in extraterrestrial planets is sparking a new interest on terrestrial aeolian geomorphology highlighting the significance of planetary studies in advancing the understanding of our Earth. Key Points: Results from the 5th International Planetary Dunes Workshop are presentedStudy of aeolian landforms can shed light on climatic changes and are key for landing site characterizationCombined use of imaging and high‐resolution flow modeling can provide new insights into the mechanism and processes that form bedforms [ABSTRACT FROM AUTHOR]

The transport of H2O ice along the retreating north polar seasonal CO2 ice cap has previously been modeled and observed. Spectral observations show that H2O ice forms on the interior of the seasonal cap, while thermal observations show these regions to be consistent with CO2 ice. Prior to the sublimation of the seasonal CO2, the observed H2O ice deposits are diminished—and because H2O ice sublimation rates are extremely slow while in direct thermal contact with CO2 ice, an alternate removal process must be operating. We propose a model where the process of removing these H2O deposits starts with insolation‐induced basal sublimation of the underlying CO2 ice. This sublimed gas would "seep" upward and into the interface between the two ices, increasing pressure until the gas pressure fractures the cold‐trapped H2O ice. Small fragments would be suspended while larger fragments would be pushed aside, exposing the underlying CO2 ice. Plain Language Summary: The atmosphere on Mars is 95% CO2. Over the winter polar region, which is in complete darkness, temperatures drop to the point where the atmosphere itself condenses onto the surface as either CO2 ice or snow. A small amount of H2O is mixed in as part of the seasonal ice. In spring, sunlight returns, and the CO2 ice starts to sublime. H2O, while only a small component in the atmosphere, interacts with the CO2 ice and becomes cold‐trapped. Once cold‐trapped, the H2O ice sublimation rate is constrained while remaining in direct thermal contact with the much colder CO2 ice. Despite this, observations in the late spring show that the H2O ice is being removed while the CO2 ice remains. We present a model where the H2O ice is removed by the activity of subliming CO2 ice. Key Points: We propose a model where the process of removing H2O deposits starts with insolation‐induced basal sublimation of the underlying CO2 iceWe used images of dawn and dusk polar clouds as a tracer for the H2O cycle over the Mars north polar seasonal capH2O vapor, cycled in from the midlatitudes, forms the observed clouds and also becomes cold‐trapped on the seasonal CO2 ice [ABSTRACT FROM AUTHOR]