Scientists are still working to understand the subtle nuances of the Mars dust storm.
REPUBLIKA.CO.ID, WASHINGTON – The massive dust storm on Mars that threatened the United States Air Force and Space (NASA) lander has finally vanished. In late September, the Mars Reconnaissance Orbiter NASA sound the alarm for the mission to study the Red Planet when sand storm is going.
Such storms have had a grim reputation among surface missions since a planet-wide hurricane ended the Opportunity solar-powered rover mission in 2018. NASA now has another solar-powered robot to worry about on the surface. its InSight lander.
For several weeks, storms left InSight alone, but by early October dust had darkened the skies above and spacecraft personnel feared their mission would abruptly end. Now, it’s clear that although the end of the InSight mission is still looming, the lander is withstanding the worst storms and dust is starting to fall from the sky, Claire Newman, an atmospheric scientist at Aeolis Research working on meteorological observations from the Spacecraft. Martian surface, told Space.
Scientists are still working to understand the nuances of the Red Planet’s glow, and in particular dust storms, Newman said. Small, localized dust storms can occur year round, but larger storms become more common as summer ends in the Southern Hemisphere, so hurricanes like the one threatening InSight don’t go beyond the norm.
“This is the kind of event we often see this time of year,” Newman said Space, Sunday (10/30/2022). “Let’s hope it goes regional. It seems, of its kind, quite large.
Hurricanes follow a seasonal rhythm as they are triggered by a thermal imbalance that lifts dust off the surface and into the thin atmosphere of Mars. There, it sets off a vicious circle. “You raise dust, the dust heats up, which tends to reduce this tribal gradient, so locally you tend to get stronger winds and therefore tend to collect more dust,” Newman said.
The orbiter can detect ongoing storms in images and temperature data, but surface missions can also identify storms, even distant storms, because dust makes the daily cycle of atmospheric pressure on Mars more dramatic. The Perseverance rover, for example, detected this pressure change in the early days of a storm, even with no dust in the sky above Jezero Crater.
“This is a global response to something that is probably only happening on a third of the planet or less,” Newman said.
It is different from global storms, which fill the entire atmosphere of the planet, from east to west, with dust. These storms can form every few years because on Mars it is difficult to stop the feedback loop triggered by dust in the atmosphere.
“There are no global-scale dust storms on Earth, and that’s partly because the dense atmosphere prevents this very strong feedback loop,” Newman said. “But it’s also because you have oceans, water and precipitation, and that pulls the dust out of the atmosphere, while on Mars you don’t have all that to slow the dust down.”
Although the recent hurricane was a major regional event, it failed to cover the entire planet. The respite likely stems from the fact that surface winds on Mars generally blow from the north at this time of year and these storms start in the south. So while the upper atmosphere in the Northern Hemisphere (where Perseverance is located) is getting a bit dusty, the storm itself may have struggled to take hold on the surface and grow north.
“It could be the time of year when it’s happening and background circulation is what makes expansion and globalization more difficult,” Newman said. “It will be difficult to expand north and into the northern hemisphere at low speeds, because the bottom flow is coming in the wrong direction.”
It’s unlikely, though not impossible, that Mars will see another major dust storm this year, Newman said. “We are probably coming to the end of the big dust storm season,” he said. “You can never say never with Mars.”
The recent hurricane was the second largest to occur on Earth this year, following a hurricane that occurred near the Perseverance rover outpost at Jezero Crater. The storm came surprisingly early in the season and was very exciting.
“This is the first time that we have made detailed observations in a location where there is active dust uplift during a storm. We are actually at the source of the storm, “she said.
