Dunes on the surface of a planet indicates it has loose sand being blown by wind.
Mars
winds
I'd have to go with "wind."
The Mojave Desert is home to several types of sand dunes, primarily including crescent-shaped barchan dunes and linear dunes. The Kelso Dunes are a notable example of barchan dunes, characterized by their crescent shape and steep slip faces. Additionally, the Mojave features some star dunes, formed by winds blowing from multiple directions, creating a complex shape. These dunes are shaped by the region's unique wind patterns and arid conditions.
The Gobi Desert primarily features cold desert conditions, characterized by harsh temperatures and minimal precipitation. Within this desert, you can find various types of sand dunes, including crescent-shaped barchan dunes and linear dunes. These dunes form due to the prevailing winds and the limited vegetation in the region, contributing to the unique landscape of the Gobi.
The Sahara Desert features several types of sand dunes, with the most prominent being crescent-shaped barchan dunes, which form in areas with limited sand supply and steady winds. Linear dunes, or seif dunes, are also common, appearing as long ridges aligned with prevailing wind directions. Additionally, star dunes, characterized by multiple arms radiating from a central point, can be found where wind directions vary. Finally, dome dunes, which are less common, have a more rounded shape and form in stable wind conditions.
It was open hard desert with sand dunes to the south.
Mars and Earth.
Seif dunes and star dunes in Algeria
There are only two sand dunes in Michigan. The two sand dunes are Sleeping Bear Dunes and Sliver lake sand dunes.
Fore dunes and back dunes but mostly fore dunes.
Primary dunes, located closest to the ocean, typically support hardy plants adapted to harsh conditions, such as high salinity, strong winds, and shifting sands. These plants, like beach grasses, have deep root systems that stabilize the dunes. In contrast, secondary dunes, found further inland, often have more nutrient-rich soils and a more diverse plant community, including shrubs and other vegetation that can tolerate slightly less extreme conditions. This variation in plant life reflects the differences in environmental stresses and soil composition between the two dune types.