There’s a certain allure to this season on Mars that brings to mind the enchantment of 1939’s The Wizard of Oz.

Maybe it’s the planet’s crimson tint, creating a natural sepia filter that recalls the film’s initial scenes. Or it could be the colossal dust devils—some so grand that they seem capable of hoisting more than just a farmhouse. One thing is for sure: if you notice one of these swirling Martian tempests, you’re certainly not in Kansas anymore. You’re approximately 140 million miles away, deep within the expanse of space.

Scientists have studied the dusty, wind-swept events on Mars for years, but NASA’s Perseverance rover recently witnessed something remarkable: a massive dust devil overtaking and engulfing a smaller one. These interactions are seldom observed, despite the frequent sightings of dust devils on the Red Planet.

“Convective vortices — or dust devils — can be quite treacherous,” stated Mark Lemmon, a Perseverance scientist with the Space Science Institute in Colorado, in a NASA statement. “These mini whirlwinds roam the Martian surface, gathering dust as they advance and reducing visibility in their vicinity. If two dust devils converge, they may either annihilate one another or merge, with the stronger one absorbing the weaker.”

The stunning occurrence was documented on Jan. 25 at the edge of Jezero Crater. The footage illustrates a large dust devil, approximately 210 feet wide, devouring a much smaller one that spans only 16 feet. As they collide, the smaller vortex vanishes into the larger one. In the backdrop, two additional dust devils swirl across the Martian terrain. Perseverance captured the spectacle from about half a mile away.

Dust devils on Mars develop similarly to those on Earth, despite the planet’s much thinner atmosphere. They usually form on dry days when the ground heats more than the surrounding air. This temperature disparity causes hot air to rise swiftly, forming a spinning column of wind that funnels upward akin to a chimney. As the vortex constricts, it speeds up—much like a figure skater spinning faster as they draw in their arms.

These Martian whirlwinds leave distinct traces—straight lines, spirals, and loops—engraved into the dusty terrain. Their trails lay bare the darker volcanic rock beneath the planet’s light, dusty exterior.

About 13 years ago, NASA’s Mars Reconnaissance Orbiter identified an exceptionally large dust devil with a plume reaching 12 miles into the atmosphere. Events like these provide valuable information about the Martian atmosphere. Scientists estimate that nearly half of the airborne dust on Mars comes from dust devils.

“Dust devils are crucial in Martian weather dynamics,” mentioned Katie Stack Morgan, a Perseverance project scientist at NASA’s Jet Propulsion Laboratory. “Investigating them aids our understanding of atmospheric factors like wind direction and speed.”

Capturing these elusive occurrences on camera is quite challenging. Unlike Earth’s hurricanes or thunderstorms, Martian dust devils appear unpredictably. Perseverance frequently scans the horizon in hopes of witnessing one in real-time. Scientists then scrutinize the images to discern patterns, such as when they are most active or their originating directions.

NASA’s Viking orbiters first captured images of Martian dust devils during the 1970s. In the 1990s, the Pathfinder lander recorded one from the Martian surface and even noted a dust devil moving overhead. Since then, various other robotic missions have observed this phenomenon, including Perseverance, which famously recorded the first audio of a Martian whirlwind in 2021.

In its latest video, Perseverance showcased the ephemeral existence of a small dust devil as it was engulfed by a larger one. However, even the surviving whirlwind likely didn’t endure for long. According to Lemmon, Martian dust devils typically last only about 10 minutes.

Nonetheless, each one provides a momentary yet invaluable insight into the vibrant and dusty landscape of Mars.