Dust devils – vertical columns of hot air and particles – appear to be a weather phenomenon unique to Earth.
But new images from NASA’s Perseverance rover show one specimen lying a whopping 1.9 kilometers high on the surface of Mars.
Perseverance captured the dust devil as it moved east-west at about 12 miles per hour along Thorofare Ridge, located on the western rim of Jezero Crater on Mars.
It was about 4 kilometers from the six-wheeled rover that landed on Mars in February 2021 after a nearly seven-month journey through space.
In addition to collecting rock samples and producing oxygen, Perseverance acts as a pair of eyes on Mars, allowing scientists to learn about the planet’s weather from 230 million miles away.
The dust devil (circled) was filmed by Perseverance from a distance of about 4 kilometers
The clip, whose speed was changed to show the devil’s progress, consists of 21 images taken four seconds apart, according to NASA.
In a blog post, scientists at the agency’s Jet Propulsion Laboratory (JPL) said the dust devil was captured by one of Perseverance’s “navcams.”
These black-and-white navigation cameras, mounted at the top of the rover’s long “neck,” use visible light to collect panoramic 3D images.
Although only the lower 387 feet (118 meters) of the swirling vortex was visible in the camera image, scientists used the dust devil’s shadow to estimate its full height at 1.2 miles (2 kilometers).
“We don’t see the tip of the dust devil, but the shadow it casts 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 this way, its shadow would indicate it is about 1.2 miles (2 kilometers) tall.”
The dust devil can be seen in the background, and regolith – a blanket of loose dust, broken rocks and other Martian fragments – in the foreground
The six-wheeled rover is on Mars to search for signs of ancient life, search for water and collect samples of Martian soil and rock with the aim of one day returning to Earth
What are dust devils?
A dust devil is a funnel-shaped chimney through which hot air flows both upward and in a circle.
They usually make themselves known through the dust, sand and debris that they pick up from the ground.
They form when hot air rises quickly through the cooler air above. If the conditions are right, a spinning effect can occur as the air rises.
Normally the dust vortices are found in dry conditions, when solar radiation is particularly strong.
Source: American Meteorological Society
The accelerated clip was captured on August 30, the 899th Martian day, or “sol,” of the Perseverance mission.
A sol consists of 24 hours and 37 minutes – a little longer than a day on Earth.
As on Earth, dust devils form when rising cells of warm air mix with descending columns of cooler air, carrying dust and debris with them.
However, due to the lower gravity and abundance of dust on our neighboring planet, the Martian versions can grow much larger than those found on Earth.
Dust devils are also most common during the spring and summer months when temperatures are warmer.
This is because the hot air near the ground rises quickly through the cooler air above, which can trigger the upward flow of air.
It is currently summer in the northern hemisphere of Mars, where Perseverance is located.
Perseverance was tasked with searching for dust devils in all directions to help scientists on the ground track Martian weather.
Images are taken in black and white to reduce the amount of data sent to Earth, meaning less waiting to see what Perseverance sees.
Dust devils are also most common during the spring and summer months when temperatures are warmer. This is because the hot air near the ground rises quickly through the cooler air above, which can trigger the upward flow of air. It is currently summer in the northern hemisphere of Mars, where Perseverance is located
A complete test model of the Perseverance rover, currently on Mars, is shown during a press conference for the Mars Sample Return mission April 11, 2023, at the Mars Yard at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California
However, the rover’s main goal is to search for traces of fossilized microbial life and collect rock samples to return to Earth.
For more than two years, it has been circling Jezero Crater, collecting rock samples and placing them in a titanium tube.
Jezero Crater was chosen as the site because scientists believe the area was once flooded with water and hosted an ancient river delta.
Secrets about this body of water, if it existed, could remain hidden in the rock samples and be uncovered by scientists on Earth.
However, Perseverance isn’t bringing the samples back to Earth – the rover is stashing the tubes in specific locations so they can be collected by a highly ambitious recovery mission.
Samples that could contain traces of ancient life are being taken from the Jezero crater near a fossilized, four-billion-year-old river delta
This joint mission between NASA and the European Space Agency (ESA) is currently in development – although it is reportedly not making much progress.
A report released last week by NASA’s Institutional Review Board suggested the launch was at risk of failing due to costs and “complexity.”
It states: “There is currently neither a credible, consistent technical timetable nor adequate scope for the schedule, cost and technical baseline that could be achieved with the resources likely to be available.”
Hard in action: NASA’s Perseverance rover and Ingenuity helicopter are searching for life on the Red Planet
NASA’s Mars 2020 mission was launched to search for signs of ancient life on the Red Planet and help scientists better understand how life evolved on Earth in the early years of the solar system’s evolution.
The vehicle-sized lead rover, called Perseverance, is exploring an ancient river delta in Jezero Crater, which was once filled with a 1,600-foot-deep lake.
The region is thought to have hosted microbial life around 3.5 to 3.9 billion years ago, and the rover will examine soil samples to look for evidence of life.
NASA’s Mars 2020 rover (artist’s impression) is searching for signs of ancient life on Mars to help scientists better understand how life evolved on our own planet
The $2.5 billion (£1.95 billion) Mars 2020 spacecraft launched on July 30 with the rover and helicopter inside – and landed successfully on February 18, 2021.
Perseverance landed in the crater and will slowly collect samples that will eventually be returned to Earth for further analysis.
A second mission will fly to the planet and return the samples, possibly by the late 2020s in collaboration with the European Space Agency.
This concept art shows the Mars 2020 rover landing on the Red Planet using NASA’s Sky Crane system