Scientists spot two kilometre-high "devil" on Mars

Scientists have spotted a two kilometre-high "devil" on Mars.

The amazing spectacle observed by NASA’s Perseverance rover was revealed to be a dust devil moving across the Martian landscape.

The six-wheeled geologist robot documented the lower portion of the twister as part of an atmospheric exploration of Jezero Crater.

The whirlwind was seen moving east to west about 19 kph (12 mph) along “Thorofare Ridge” on August 30.

NASA JPL-Caltech explain: "Much weaker and generally smaller than Earth’s tornadoes, dust devils are one of the mechanisms that move and redistribute dust around Mars.

"Scientists study them to better understand the Martian atmosphere and improve their weather models."

Using data from the imagery, mission researchers determined that this particular dust devil was about four kilometres (2.5 miles) away.

They calculated its width to be about 60 metres (200 ft). And while only the bottom 118 metres (387 feet) of the swirling vortex are visible in the camera frame, the scientists could also estimate its full height.

“We don’t see the top of the dust devil, but the shadow it throws gives us a good indication of its height,” said Mark Lemmon, a planetary scientist at the Space Science Institute in Boulder, Colorado, and a member of the Perseverance science team. “Most are vertical columns. If this dust devil were configured that way, its shadow would indicate it is about 1.2 miles (2 kilometers) in height.”

Dust devils, which also occur on Earth, form when rising cells of warm air mix with descending columns of cooler air.

JPL-Caltech explain: "The Martian versions can grow to be much larger than those found on Earth. And while they are most prominent during the spring and summer months (Mars’ northern hemisphere, where Perseverance is located, is currently in summer), scientists can’t predict when they’ll appear at a specific location.

"So Perseverance and its fellow NASA Mars rover Curiosity routinely monitor in all directions for them, taking images in black-and-white to reduce the amount of data sent to Earth."