In the thin, dusty atmosphere of Mars, a sunny day can be a prelude to chaos.
Planetary scientists at the University of Colorado Boulder have found that warm, sunlit days may set the stage for massive dust storms — the kind that can bury a rover, stall a mission, and, one day, potentially endanger astronauts. While Earth’s storms swirl with wind and rain, Mars unleashes clouds of fine, gritty dust that sometimes engulf the entire planet in a rust-colored haze.
These storms, it turns out, may be triggered by the same kind of heat-driven turbulence we experience back home.
“This dust is very light and sticks to everything,” said Heshani Pieris, the lead author of the study and a graduate student at CU Boulder’s Laboratory for Atmospheric and Space Physics (LASP). Dust storms, she noted, pose real risks for Mars exploration.
The Warm-Up Before the Storm
Pieris and her colleagues studied weather data from NASA’s Mars Reconnaissance Orbiter (MRO), which has been observing the Red Planet since 2006. Specifically, they examined temperature patterns captured by the Mars Climate Sounder, an instrument designed to track atmospheric conditions.
The team’s findings are striking: Around 68% of major dust storms are preceded by a sharp rise in surface temperatures. In other words, the planet warms up, and then, a few weeks later, a storm kicks up. It’s as if Mars needs a clear, calm stretch of warmth before it unleashes a frenzy of dust.
“It’s almost like Mars has to wait for the air to get clear enough to form a major dust storm,” said Paul Hayne, an associate professor at CU Boulder and co-author of the study.
On Earth, this process is familiar. During hot summers, warm air near the ground rises, sometimes forming towering storm clouds. On Mars, the heat from the sun causes the atmosphere near the surface to become buoyant, lifting dust particles high into the sky.
“When you heat up the surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it,” Pieris explained.
These findings were presented at the recent American Geophysical Union meeting, offering a critical step toward predicting the planet’s most unpredictable weather.
Storms of Consequence
For decades of observation, Mars’ dust storms have been both a spectacle and a hazard. In 1971, NASA’s Mariner 9 (the first spacecraft ever to orbit Mars) arrived to find the entire planet obscured by a dust storm, its surface hidden beneath a swirling shroud. The storms range from regional events to planet-encircling monsters that can last for weeks or even months.
In 2018, one such storm proved fatal for NASA’s Opportunity rover. The storm’s dust coated Opportunity’s solar panels, depriving it of power. After 15 years of exploration, the resilient rover fell silent, buried beneath a layer of fine Martian grit.
Even the more recent, nuclear-powered Perseverance rover faced difficulties. A smaller storm in September briefly curtailed its scientific activities.
“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.
Future human explorers on Mars will need to contend with this gritty reality. Dust storms can reduce visibility, disrupt communications, and potentially damage habitats and equipment. Forecasting them, therefore, is crucial.
Forecasting Dust Storms on Mars
The team at CU Boulder hopes their research will lead to accurate predictions, much like weather forecasts on Earth. While Mars weather forecasters may not be ready for prime time, Pieris and Hayne see this as a promising start.
“We need to understand what causes some of the smaller or regional storms to grow into global-scale storms,” Hayne said. “We don’t even fully understand the basic physics of how dust storms start at the surface.”
The researchers are now analyzing more recent data, searching for patterns that could reveal the mechanisms behind these explosive events. Their goal is to one day use real-time data to predict dust storms before they strike.
“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.”
