Seasonal dust storms are well-known on Mars, and they can sometimes cover the entire planet.
The dust storms got so intense in June 2018 that they hid most of the planet's surface, prompting NASA to lose touch with Opportunity, which proved catastrophic for the world-record-breaking rover.
Understanding these storms and what generates them is essential for solar-powered robotic missions to continue operating and future crewed missions to be safe.
Seasonal fluctuations (i.e., changes in absorbed solar energy and temperature rises) that start dust storms and drive them to mix and expand are what scientists are looking for.
They could be caused by seasonal energy imbalances in the quantity of solar energy collected and released by the earth, according to a recent study undertaken by researchers from the University of Houston.
These discoveries may lead to a better understanding of Mars' climate and atmosphere.
As part of her doctoral thesis, Ellen Creecy, a Ph.D. student in the Department of Earth and Atmospheric Sciences (EAS) at the University of Houston, led the research.
At the Lunar Planetary Institute, she was joined by Dr. Xun Jiang and Dr. Liming Li (her EAS thesis advisors), as well as researchers from NASA's Goddard Space Flight Center, NASA's Jet Propulsion Laboratory, and the Universities Space Research Association (USRA) (LPI).
The researchers combined data from various missions, including the Mars Global Surveyor (MGS), the Curiosity rover, and the InSight lander, for their research.
This allowed them to simulate Mars' environment and calculate the amount of energy it emitted globally as a function of season, including periods when the planet was covered in dust.
"One of the most interesting findings is that energy excess – more energy being absorbed than produced – could be one of the generating mechanisms of dust storms on Mars," Creecy added.
The seeds of the storm were caught brewing in the enormous Hellas Basin (oval at 4 o'clock on disk) and another storm at the northern polar cap when the Hubble Space Telescope scanned Mars in June 2001 (left).
The findings found that the amount of solar energy released by Mars varies greatly by season and day.
They discovered a significant energy imbalance of 15.3 percent between Mars' seasons, compared to 0.4 percent on Earth. They also discovered that during the 2001 dust storm that encircled the globe, the quantity of power emitted globally reduced by 22% during the day but increased by 29% at night.
In a recent USRA press release, Dr. Germán Martnez, a USRA staff scientist at the Lunar and Planetary Institute (LPI) and a co-author of the article, explained:"Our results showing strong energy imbalances suggest that current numerical models should be revisited, as these typically assume that Mars' radiant energy is balanced between Mars' seasons. Furthermore, our results highlight the connection between dust storms and energy imbalances, and thus can provide new insights into the generation of dust storms on Mars."
The team's findings, when combined with numerical simulations of Mars' environment, could help us better grasp the Martian climate and atmospheric circulations. This will be critical for future crewed missions to Mars, which NASA and China aim to launch in the next decade.
Furthermore, these insights may help us better comprehend Earth's climate by predicting how our environment will react in the future. As is always the case, learning more about other planetary settings leads to a better understanding of our own.
