Warm spells on Mars may spark massive dust storms, scientists say, bringing us closer to predicting Martian weather.
Today’s weather report on Mars: Windy with a chance of catastrophic dust storms blotting out the sky.
A new study from planetary scientists at the University of Colorado Boulder sheds light on the origins of Mars’ planet-wide dust storms—powerful weather events capable of obscuring the entire sky in swirling dust.
The research reveals that relatively warm and sunny days on Mars may play a key role in triggering these massive storms. According to lead author Heshani Pieris, the findings mark an important step toward eventually being able to forecast extreme Martian weather, much like meteorologists do on Earth.
“Dust storms have a significant effect on rovers and landers on Mars, not to mention what will happen during future crewed missions to Mars,” said Pieris, a graduate student at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. “This dust is very light and sticks to everything.”
She recently presented the results at the 2024 meeting of the American Geophysical Union in Washington.
To put dust storms under the magnifying glass, the researchers drew on real observations from NASA’s Mars Reconnaissance Orbiter satellite.
So far, they have identified weather patterns that may underly roughly two-thirds of the major dust storms on Mars. You won’t see Mars weather reporters standing in front of a green screen just yet, but it’s a step in the right direction, said study co-author Paul Hayne.
“We need to understand what causes some of the smaller or regional storms to grow into global-scale storms,”
said Hayne, a researcher at LASP and associate professor at the Department of Astrophysical and Planetary Sciences. “We don’t even fully understand the basic physics of how dust storms start at the surface.”
Dusty demise
Dust storms on Mars are something to behold.
Many begin as smaller storms that swirl around the ice caps at the planet’s north and south poles, usually during the second half of the Martian year. (A year on Mars lasts 687 Earth days). Those storms can grow at a furious pace, pressing toward the equator until they cover millions of square miles and last for days.
The 2015 film The Martian starring Matt Damon featured one such apocalyptic storm that knocked over a satellite dish and tossed around astronauts. The reality is less cinematic. Mars’ atmosphere is much thinner than Earth’s, so dust storms on the Red Planet can’t generate much force. But they can still be trouble.
In 2018, for example, a global dust storm buried the solar panels on NASA’s Opportunity rover under a layer of dust. The rover died not long after.
“Even though the wind pressure may not be enough to knock over equipment, these dust grains can build up a lot of speed and pelt astronauts and their equipment,” Hayne said.
Hot spells
In the current study, Pieris and Hayne set their sights on two weather patterns that tend to occur every year on Mars known as “A” and “C” storms.
The team pored over observations of Mars from the Mars Climate Sounder instrument aboard the Mars Reconnaissance Orbiter over eight Mars years (15 years on Earth). In particular, Pieris and Hayne looked for periods of unusual warmth—or weeks when more sunlight filtered through Mars’ thin atmosphere and baked the planet’s surface.
They discovered that roughly 68% of major storms on the planet were preceded by a sharp rise in temperatures at the surface. In other words, the planet heated up, then a few weeks later, conditions got dusty.
“It’s almost like Mars has to wait for the air to get clear enough to form a major dust storm,” Hayne said.
The team can’t prove that those balmy conditions actually cause the dust storms. But, Pieris said, similar phenomena trigger storms on Earth. During hot summers in Boulder, Colorado, for example, warm air near the ground can rise through the atmosphere, often forming those towering, gray clouds that signal rain.
“When you heat up the surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it,” Pieris said.
She and Hayne are now gathering observations from more recent years on Mars to continue to explore these explosive weather patterns. Eventually, they’d like to get to the point where they can look at live data coming from the Red Planet and predict what could happen in the weeks ahead.
“This study is not the end all be all of predicting storms on Mars,” Pieris said. “But we hope it’s a step in the right direction.”
Meeting: AGU 2024
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