Arrakis is the desert planet Dune, but Mars is making a play for the title. On the floor of a crater known as Airy-o on the Red Planet, dunes ripple like waves. Here’s more from Astronomy Now:
There’s no Greenwich Observatory on Mars, so planetary scientists use…Airy-0 to define zero degrees longitude on the red planet. Airy-0 actually sits within an even larger crater that was originally used to define the prime meridian but as higher-resolution maps became available based on imagery from more powerful satellites, a smaller feature was needed. Airy-0 fit the bill and required no adjustment of any existing maps.
Source: https://blog.adafruit.com/2022/01/29/rippling-sand-dunes-on-mars-spaesaturday/