A monster dust devil in action in Mars' Amazonis Planitia region | Watch

 

Video Credit: NASA/JPL-Caltech/UArizona

In a stunning afternoon image of Mars' Amazonis Planiti captured by NASA's HiRISE camera, a colossal dust devil resembling a terrestrial tornado has been spotted hovering over the Martian surface.

Standing at a height comparable to a towering tornado on Earth, this incredible dust plume reaches a staggering 20 kilometers above the planet's surface, as indicated by the length of its shadow, with the continuous column of dust reaching half that altitude. Despite its immense proportions, the dust devil's diameter measures a mere 140 meters, twisting in a serpentine fashion due to powerful high-altitude winds.

On Earth, typical tornadoes are less than 10 miles tall, while dust devils seldom reach more than a few hundred yards in height. Then why is it considered a monster dust devil rather than a Martian tornado? The distinction lies in their energy sources - while tornadoes on Earth rely on the heat generated as water vapor condenses into rain, dust devils on Mars derive their energy from the surface's heat, absorbed from sunlight and radiated back into the atmosphere. As the warm air rises and contracts, it spins, akin to the principle of a figure skater spinning faster when drawing their arms closer to their sides.

On Mars, the scarcity of water vapor in the atmosphere hampers significant atmospheric convection on local scales, preventing the formation of tornadoes.The cloud visible in this image is produced by dust particles, not raindrops.

The astounding heights achieved by these dust devils can be attributed to the lower mass of the Martian atmospheric column, which is less than 1 percent of Earth's column. With a less dense atmosphere, the transfer of surface heat leads to more vigorous convection, propelling the dust devils to penetrate higher into the Martian atmosphere than their earthly counterparts.

Wondering what would happen if you were caught in the path of such a colossal Martian dust devil? Here's what the HiRISE team has to say:

Due to the low density of Mars' atmosphere, even a high-velocity dust devil is unlikely to knock a person over. However, the barrage of sand and dust particles carried by the dust devil could pelt and potentially scratch a space suit's visor, necessitating caution if caught outside by this monster.

This vortex has etched a bright track on the dusty surface, revealing the path of the dust devil from the northwest to the southeast. A dust "skirt" twice the width of the plume itself is visible near the base of the dust devil. Additionally, dozens of smaller dust devils were spotted in the same scene, diligently vacuuming the surface and propelling dust into the Martian atmosphere. The combined spectacle showcases the dynamic and ever-changing nature of Mars' atmospheric phenomena.