In 1971, NASA’s Mariner 9 spacecraft arrived at Mars only to find the planet’s surface entirely obscured from view, hiding beneath a blanket of dust that had been kicked up by a massive storm. Mars’ infamous dust storms periodically engulf the entire planet, with tiny particles spreading across the surface at a howling pace.
The other worldly storms threaten missions to Mars as the dust sticks onto the surface of robotic explorers of the Red Planet, sometimes leading to their untimely deaths. A team of planetary scientists from the University of Colorado Boulder may have figured out the factors that lead to a giant dust storm on Mars, which can often begin with a seemingly pleasant Martian day. The findings were presented on Tuesday at the meeting of the American Geophysical Union in Washington, and could have major implications for future human missions on Mars.
Using observations from NASA’s Reconnaissance Orbiter, the scientists behind the new findings were able to identify the weather patterns that may underlie roughly two-thirds of major dust storms on Mars. The team discovered that warm and sunny weather may help trigger the dust storms.
The Mars Climate Sounder instrument on board the Reconnaissance Orbiter has been collecting data on the planet’s atmosphere and terrain over the past 15 years. The scientists pored over the data in search of periods of unusual warmth, when more sunlight filters through Mars’ thin atmosphere and warms the planet’s surface. They found that around 68% of major storms on Mars were preceded by a sharp rise in temperatures at the surface.
Although it’s hard to prove a direct correlation between the hot and sunny days on Mars that are often followed by dusty conditions a few weeks later, similar conditions can lead to storms on Earth. “When you heat up the surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it,” Heshani Pieris, a graduate student at the Laboratory for Atmospheric and Space Physics at CU Boulder, and lead author of the new study, said in a statement. “It’s almost like Mars has to wait for the air to get clear enough to form a major dust storm.”
Mars’ storms can sometimes be large enough to be seen by telescopes on Earth. Relatively big storms pop up on Mars every year, covering large areas on the planet and lasting for weeks at a time. Beyond the moderate annual storms, however, a planet-encircling storm will rise once very three Martian years (5.5 years on Earth), according to NASA.
Those bad boys are the ones we need to worry about. In June 2018, a massive dust storm covered the Opportunity rover’s solar panels, forcing NASA to say goodbye to its Martian robot. As NASA plans on landing astronauts on Mars by 2030, the planet’s dust storms could pose a risk to human missions. That’s why scientists are studying the causes of these dust storms to improve predictions of when they might occur.
“We need to understand what causes some of the smaller or regional storms to grow into global-scale storms,” Paul Hayne, associate professor at the Department of Astrophysical and Planetary Sciences at CU Boulder, and co-author of the study, said in a statement. “We don’t even fully understand the basic physics of how dust storms start at the surface.”
The team behind the new study will continue piecing together the weather patterns on Mars that can lead to the giant storms. “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.”
