Mars orbiters have captured dust devils thundering across the plains of Mars before – but on March 14, the Mars Reconnaissance Orbiter snapped a 12-mile-high monster.
The length of the shadow indicates that the dust plume reached a height of 12 miles above the surface.
Dozens of smaller dust devils were captured by the Mars Reconnaissance orbiter’s cameras, ‘vacuuming’ the surface around the monster ‘devil’.
Despite its gargantuan height, the plume is only 70 yards in diameter, giving it a snake-like appearance that is twisted by high altitude winds, similar to another dust devil spotted recently in this region.
Despite the atmosphere on Mars being desperately thin – one per cent of Earth’s pressure – the planet’s winds are strong enough to produce dramatic events and in the area observed, paths of many previous whirlwinds, or dust devils, are visible as streaks on the dusty surface.
‘Because the density of Mars’ atmosphere is so low, even a high velocity dust devil is unlikely to knock you over,’ says the University of Arizona team which posted the video.
‘However, you might be blasted by any sand or dust particles carried along by the dust devil, which might scratch the visor of your space suit quickly if you were caught outside by this monster.’
Just as on Earth, winds on Mars are powered by solar heating. Exposure to the sun’s rays declines during this season, yet even now, dust devils act relentlessly to clean the surface of freshly deposited dust, a little at a time.
Dust devils occur on Earth as well as on Mars. They are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground.
As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right.
One of its cameras is so powerful they can reveal objects on Mars as small as an office desk.
It has taken over 20,000 photographs of the Red Planet so far.
The Orbiter makes a complete circuit of Mars every 112 minutes, flying a nearly circular orbit that ranges in height from about 255 kilometers (160 miles) over the South Pole to 320 kilometers (200 miles) over the North Pole.
For handling large amounts of data, Mars Reconnaissance Orbiter has 160 gigabits of solid-state memory and a processor operating at up to 46 million instructions per second.
Explanation of the Martian dust devil construction:
Below is video animation of the Martian dust devil: