NASAMAVEN detected a unique solar phenomenon that had a significant impact on Mars” Observe the atmosphere and provide important insights into the interaction of Earth and solar phenomena.
In December 2022, NASA’s MAVEN (Mars Atmosphere and Volatile EvolutioN) mission observed a dramatic and unexpected “disappearance” of the stream of charged particles constantly emitted by the Sun, known as the solar wind. It was caused by a special type of solar phenomenon that was so powerful that it left a gap in its wake as it passed through the solar system.
Due to this phenomenon, MAVEN measurements on Mars showed a significant reduction in the number of particles that make up the solar wind. Without the pressure of the solar wind, Mars’ atmosphere and magnetosphere would have expanded by thousands of kilometers. MAVEN is the only facility currently on Mars that can simultaneously observe both the sun’s activity and the response of the Martian atmosphere to solar impacts.
“When we first saw the data and how dramatic the reduction in the solar wind was, it was almost unbelievable,” said Jasper Harekas, a professor at the university. University of Iowa and lead author of a new study on the event. “We formed a working group to study this event, and found that this period was rich in surprising discoveries.”
Learn about the “disappearance” of Mars’ solar wind witnessed by MAVEN. The last time this event was seen on Earth was almost a quarter of a century ago.Credit: NASA’s Goddard Space Flight Center
Understanding the disappearance of the solar wind
Mars, like other planets in the solar system, is constantly exposed to the solar wind. The solar wind puts pressure on Mars’ magnetosphere and ionosphere, causing atmospheric escape. The December 2022 solar event was caused by the faster-moving solar wind overtaking the slower-moving solar wind, acting like a broom, sweeping and compressing the two regions together. This interaction, called the stream interaction region, leaves in its wake a rare void of extremely low density solar wind, which was observed by his MAVEN. This “disappearance” of the solar wind caused incredible interactions within Mars’ magnetosphere and ionosphere.
Event result
When the density of the solar wind was reduced by a factor of 100, the pressure dropped and the planet’s magnetosphere and ionosphere could expand by thousands of kilometers (more than three times their normal size), dramatically changing their properties. The sun’s magnetic field, which is normally embedded within Mars’ ionosphere, was pushed outward, changing the ionosphere from a magnetized state to an unmagnetized state. At the same time, the layer between the solar wind and the magnetosphere became unusually electromagnetically quiet. His MAVEN observations of this dramatic event and the subsequent changes and expansion of the entire system are important for a deeper understanding of the physics driving Mars’ atmosphere and water loss.
“We’re really starting to see how Mars responds when the solar wind is effectively removed,” Harekas added. “This is a great outlier study of what would happen if Mars orbited a star with weak winds.”
The importance of MAVEN observations
This was the first time the MAVEN mission had the opportunity to observe a solar wind extinction event of this magnitude, as it is extremely rare and occurs during periods of high solar activity. Other rovers on Mars and Earth also observed aspects of this event, but his MAVEN was the only one that was able to simultaneously measure both the Sun and the Martian atmosphere’s response to it.
“Observations of extreme conditions are always extremely valuable scientifically,” said MAVEN principal investigator Shannon Currie. University of California, Berkeley. “MAVEN was designed to observe this type of interaction between the Sun and Mars’ atmosphere, and the spacecraft provided excellent data during this truly unusual solar phenomenon. ”
The MAVEN mission could have an even bigger impact on our understanding of extreme solar events, as the Sun moves toward its solar maximum, the peak of its 11-year cycle.
Collaborative initiatives and future plans
“This shows that MAVEN is playing a cross-functional role on Mars,” said MAVEN deputy principal investigator and associate director of the Heliophysical Sciences Division at NASA Goddard Space Flight Center in Greenbelt, Maryland. said one Gina DiBraccio. “MAVEN is not only observing the dynamics of Mars’ atmosphere, but also monitoring solar inputs to improve our understanding of the Sun.”
The research will be presented at the American Geophysical Union Fall Meeting in San Francisco.
MAVEN’s principal investigator is based at the University of California, Berkeley, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN mission. Lockheed Martin Space manufactures the spacecraft and is responsible for mission operations. NASA’s Jet Propulsion Laboratory in Southern California provides navigation and deep space network support. The Atmospheric and Space Physics Laboratory at the University of Colorado Boulder is responsible for managing scientific activities and public activities and communications. The MAVEN team is preparing to celebrate its 10th anniversary on Mars in September 2024.