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When the Sun unleashed an extreme solar storm and slammed into Mars in May, it engulfed the red planet in an aurora and a flood of charged particles and radiation, according to NASA.
The sun has been more active in the past year as it nears the top of its 11-year cycle, called solar maximum, which is expected to occur later this year.
Recent months have seen a surge in solar activity, such as X-class flares, the most powerful of the solar flares, and coronal mass ejections, or large clouds of ionized gas called plasma and magnetic fields that erupt from the Sun’s outer atmosphere.
Solar storms that arrived on Earth in May produced colorful auroras that danced in the sky over areas that rarely experience them, such as Northern California and Alabama.
The storms originated from a massive cluster of sunspots that accidentally came close to Earth. Then the sunspot cluster turned in the direction of Earth’s cosmic neighbor: Mars.
Astronomers have used a number of orbiters circling the red planet, as well as rovers traveling across its surface, to capture first-hand the effects of a solar storm on Mars – and to better understand what radiation levels the first astronauts on the red planet may experience. future.
The most extreme storm occurred on May 20 after X12 erupted from the Sun, according to data collected by the Solar Orbiter, which is currently studying the Sun.
The massive eruption sent X-rays and gamma rays hurtling towards Mars, and the coronal mass ejection quickly broke loose on the heels of the eruption, hurling charged particles in the direction of the red planet.
X-rays and gamma rays traveled at the speed of light and reached Mars first, followed by charged particles within tens of minutes, according to scientists tracking activity from NASA’s Moon to Mars Space Analysis Office at the Goddard Space Flight Center in Greenbelt, Maryland.
The Curiosity rover, currently exploring Gale Crater south of the Martian equator, captured black-and-white images using its navigation cameras during the solar storm. The white snow-like streaks seen in the images are the result of charged particles impacting Curiosity’s cameras, according to NASA.
The energy from the sun’s particles was so strong that the star camera aboard the Mars Odyssey orbiter, which helps orient the probe as it orbits the planet, momentarily shut down. Fortunately, the spacecraft managed to turn the camera back on within an hour. The last time Odyssey faced such extreme solar behavior was during solar maximum in 2003, when the X45 eruption burned out the orbiter’s radiation detector.
NASA/Caltech-JPL/MSSS
Fifty-seven images make up this selfie taken by the Curiosity Mars rover at one of its training sites in January 2019.
Meanwhile, Curiosity used its Radiation Assessment Detector, or RAD, to measure the amount of radiation hitting the planet during the storm. An astronaut standing next to the rover would experience radiation equivalent to 30 chest X-rays, which is not fatal, but is the largest such increase in radiation measured by the rover’s instruments since landing nearly 12 years ago.
Understanding the maximum radiation that astronauts can experience on the red planet helps scientists plan how to protect those involved in future manned exploration of Mars.
“Cliffs or lava tubes would provide additional shielding to the astronaut from such an event.” In Mars orbit or in deep space, the dose rate would be significantly higher,” said Don Hassler, RAD principal investigator in the Southwest Research Institute’s Solar System Science and Exploration Division in Boulder, Colorado. “I wouldn’t be surprised if this active region on the Sun continues to erupt, meaning even more solar storms on Earth and Mars in the coming weeks.”
The MAVEN orbiter, short for Mars Atmosphere and Volatile EvolutioN, had an aerial view of the auroras dancing in ultraviolet light over Mars during a solar storm. The orbiter launched to Mars in 2013 to study how the red planet has lost its atmosphere over time and how space weather generated by the Sun interacts with the upper Martian atmosphere.
But these auroras appear to be very different from the aurora borealis or aurora borealis and the southern lights or aurora borealis that occur on Earth.
When energized particles from coronal mass ejections reach the Earth’s magnetic field, they interact with gases in the atmosphere to create different colored lights in the sky, specifically near its poles.
But Mars lost its magnetic field billions of years ago, meaning the planet has no shield from incoming charged solar particles. So when the particles hit the thin atmosphere of Mars, the reaction results in auroras engulfing the planet.
“Because Mars does not have a global magnetic field, Martian auroras are not concentrated at the poles like they are on Earth, but instead appear as a ‘global diffuse aurora’ associated with the ancient magnetized crust of Mars,” wrote Deborah Padgett. , Operational Product Generation Subsystem task leader at NASA’s Jet Propulsion Laboratory in Pasadena, California, on the space agency’s Curiosity rover blog.
Future astronauts may one day witness these Martian light shows, according to NASA.
By tracking data from several Mars missions, scientists were able to track how the solar storm developed.
“This was the largest solar energetic particle event MAVEN has ever seen,” MAVEN Space Weather lead Christina Lee of the University of California, Berkeley’s Space Sciences Laboratory said in a statement. “There have been several solar events in the past few weeks, so we’ve seen wave after wave of particles hitting Mars.”