Martian dust devils

They were discovered from data reported by NASA's Viking probes, and have been photographed by orbiting satellites and surface rovers in subsequent missions.

[2] Orbital photographs previously taken by Mariner 9 also showed surface lineations initially thought to be the ridges of seif dunes, but they were also shown to be dust devil tracks based on the data from Viking.

The Mars Pathfinder rover detected 79 convective vortices through atmospheric pressure data, and imaged several dust devils with its wide-angle camera.

[2] On 7 November 2016, five dust devils ranging in height from 0.5 to 1.9 kilometers (0.31 to 1.18 mi) were imaged in a single observation by the Mars Orbiter Mission in the Martian southern hemisphere.

[4] On 27 September 2021, the Perseverance rover directly encountered a Martian dust devil, imaging and recording the sound of the vortex as it passed, the first such observation in the history of Mars exploration.

Even though only the bottom 387 feet (118 meters) of the devil was visible in the camera frame, scientists estimated its total height at about 1.2 miles (2 kilometers) based on the length of its shadow[6]---higher than the average tornado on Earth.

[8][9] The greater height of Martian dust devils may be due to a planetary boundary layer which is several kilometers thicker on average than Earth's.

[13] Sudden, unexpected recovery of power output was also experienced periodically by the Opportunity and Sojourner rovers, considerably expanding their operational lifetimes.