A dust devil, a type of extraterrestrial whirlwinds (a mini-tornado, so to say), has been spotted by NASA’s Mars rover Opportunity which has been navigating the surface of Mars for over a decade now.
The Mars rover Opportunity of NASA was out there on the Martian surface in an area called the Knudsen Ridge where studies are focused because of the possible presence of clays that have been formed in chemical processes involving ancient surface water. This region of Mars is, therefore, considered to be of great importance when it comes to looking into Mars’ past that might indicate signs of water on the planet. That was the spot from where the rover captured a dust devil swirling in a neighbouring valley called Marathon Valley; Knudsen Ridge is actually found bordering the southern part of the valley. The event happened on March 31.
Dust devils constitute a common sight on Mars. However, Opportunity has not captured many of them. Another rover called Spirit has, however, been more acquainted with the phenomenon in Gusev Crater. Unfortunately, Spirit lost contact with the Earth 6 years ago, and from then on, we could only see dust devils from the High-Resolution Imaging Science Experiment (HiRISE) camera that is set up on Mars Reconnaissance Orbiter (MRO) of NASA.
How does this atmospheric event occur? According to scientists, it is formed in a similar fashion as those on Earth. A thin air layer situated above the ground rises when heated by sunlight; its rotation thereafter causes the creation of a small pocket of low pressure that ultimately turns into a fast-spinning vortex that is able to suck up dust from the surface. Dust devils can reach up to hundreds of meters in height. They are believed to have an important function on Mars’ surface: they apparently bring about dust cycling, thereby setting the balance in terms of the global climate of the planet.
This air movement can prove to be useful to rovers sent to Mars as well. For instance, they might sometimes reach Opportunity‘s solar panels and end up cleaning them.