In 1971, NASA‘s Mariner 9 spacecraft arrived on Mars to find the planet’s surface completely hidden from view, hiding under a blanket of dust kicked up by a powerful storm. The infamous dust storms on Mars periodically cover the entire planet, and tiny dust particles fly across the surface at howling speeds.
The otherworldly storms threaten missions to Mars as the dust sticks to the surface of robotic explorers on the Red Planet, sometimes leading to their premature death. A team of planetary scientists from the University of Colorado at Boulder may have figured out the factors that lead to a giant dust storm on Mars, which can often start with a seemingly pleasant Martian day. The findings were presented on Tuesday at the American Geophysical Union meeting in Washington, D.C., and could have major implications for future human missions to Mars.
Using observations from NASA’s Reconnaissance Orbiter, scientists were able to identify weather conditions that may underlie about two-thirds of the large dust storms on Mars. The team found that warm and sunny weather can contribute to dust storms.
The Mars Climate Sounder instrument aboard the Reconnaissance Orbiter has been collecting data on the planet’s atmosphere and topography for the past 15 years. Scientists analyzed the data to look for periods of unusual heat, when more sunlight penetrated Mars’ thin atmosphere and warmed the planet’s surface. They found that about 68% of major storms on Mars were preceded by a sharp rise in surface temperature.
Although it is difficult to prove a direct link between hot and sunny days on Mars, which are often followed by dusty conditions a few weeks later, similar conditions can lead to storms on Earth. “When you heat up a surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it,” Heshani Paris, a graduate student at the Boulder Laboratory for Atmospheric and Space Physics and lead author of the new study, said in a statement. “It looks like Mars must wait until the air is clear enough to form a large dust storm.”
Martian storms are sometimes large enough to be seen with telescopes on Earth. Relatively large storms occur on Mars every year, covering large areas of the planet and lasting for weeks. However, according to NASA, in addition to moderate annual storms, a storm that covers the planet occurs every three Martian years (5.5 years on Earth).
These are the ones we should be concerned about. In June 2018, a powerful dust storm covered the solar panels of the Opportunity rover, forcing NASA to say goodbye to the Martian robot. With NASA planning to land astronauts on Mars by 2030, dust storms on the planet 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 smaller or regional storms to develop into global-scale storms,” said Paul Hayne, an associate professor of astrophysical and planetary sciences at CU Boulder and co-author of the study. “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 to piece together the weather conditions on Mars that could lead to giant storms. “This study is not the end point in predicting storms on Mars,” Pieris said. “But we hope it’s a step in the right direction.”
