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When the sun unleashed a massive solar storm and hit Mars in May, it showered the red planet with auroras and an influx of charged particles and radiation, according to NASA.
The sun has been showing more activity over the past year as it approaches the peak of its 11-year cycle, known as solar maximum, which is expected to occur later this year.
In recent months, there has been a spike in solar activity, such as X-class flares, the strongest solar flares, and coronal mass ejections, or large clouds of ionized gas called plasma and magnetic fields that push out of the sun’s outer atmosphere .
Solar storms that reached Earth in May sparked colorful auroras that danced in the skies over areas that rarely experience them, such as Northern California and Alabama.
The storms came from a huge cluster of sunspots that happened to face the Earth. Then, that sunspot cluster rotates toward Earth’s cosmic neighbor: Mars.
Astronomers have used multiple orbiters around the red planet, as well as rovers driving across its surface, to directly capture the effects of a solar storm on Mars – and to better understand the radiation levels that could have the first astronauts on the red planet. in the future.
Solar radiation hits Mars
The largest storm occurred on May 20 after flare X12 was released from the sun, according to data collected by the Solar Orbiter spacecraft currently studying the sun.
The massive flare sent X-rays and gamma-rays hurtling toward Mars, and a coronal mass ejection quickly followed the flare, sending charged particles toward the red planet.
The X-rays and gamma rays traveled at the speed of light and reached Mars first, followed by the charged particles within ten minutes, according to scientists who track the activity from NASA’s Moon to Mars Office of Space Weather Analysis at the Center Goddard Space Flight i. Greenbelt, Maryland.
The Curiosity rover, which is exploring Gale Crater just south of the Martian equator, took black and white images using its navigation cameras during the solar storm. White streaks like snow, visible in the images, are the result of charged particles that hit Curiosity’s cameras, according to NASA.
The energy from the solar particles was so strong that the star camera on board the Mars Odyssey orbiter, which helps focus the probe as it orbits the planet, is currently stopped. Fortunately, the spacecraft was able to turn the camera back on within an hour. The last time Odyssey encountered such extreme solar activity was during solar maximum in 2003, when the X45 flare fried the orbiter’s radiation detector.
Meanwhile, Curiosity used its Radiation Assessment Detector, or RAD, to measure the amount of radiation that hit the planet during the storm. An astronaut standing next to the rover would have experienced radiation equivalent to 30 chest X-rays, which is not fatal, but is the largest such radiation surge measured by the rover’s instrument since the he landed almost 12 years ago.
Understanding the peak radiation exposure to astronauts on the red planet helps scientists plan how to protect future crewed Mars probes.
“Cliff sides or lava tubes would provide additional protection for an astronaut from such an event. In Mars orbit or in deep space, the dose rate would be much greater,” Don Hassler, RAD principal investigator at Southwest Research Institute’s Solar System Science and Exploration Division in Boulder, Colorado, said in a statement . “I wouldn’t be surprised if this active region on the Sun continues to erupt, meaning more solar storms on Earth and Mars in the coming weeks.”
Auroras on the red planet
The MAVEN orbiter, short for Mars Atmosphere and Volatile Evolution, captured an aerial view of auras dancing in ultraviolet light above Mars during a solar storm. The orbiter launched to Mars in 2013 to study how the red planet lost its atmosphere over time and how space weather generated by the sun interacts with the upper Martian atmosphere.
But the appearance of these auroras is very different from the northern lights, or aurora borealis, and southern lights, or aurora australis, that occur on Earth.
When the energetic particles from the 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 shielding from incoming solar particles. Therefore, when the particles hit the thin atmosphere of Mars, the reaction results in planetary auroras.
“Due to the lack of a global magnetic field on Mars, Martian aurorae are not concentrated at the poles as they are on Earth, but instead appear as ‘diffuse global auroras’ associated with the ancient magnetized crust of Mars,” wrote Deborah Padgett. , the Operational Product Generation Subsystem task leader at NASA’s Jet Propulsion Laboratory in Pasadena, California, in the space agency’s Curiosity rover blog.
Future astronauts may one day be able to witness these Martian light shows, according to NASA.
By tracking the data from multiple Martian missions, scientists were able to watch how the solar storm evolved.
“This was the largest energetic solar particle event ever seen by MAVEN,” Christina Lee, MAVEN’s Space Weather Lead, from the University of California, Berkeley’s Space Sciences Laboratory, said in a statement. “There have been multiple solar events over the past few weeks, so there’s been wave after wave of particles hitting Mars.”
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