The same giant sunspot responsible for creating a historic geomagnetic storm on Earth in mid-May produced a legendary storm for Mars a few days later.
On May 20, data from the European spacecraft Solar Orbiter showed that an estimated X12 solar flare - the strongest type on the flare rating scale - erupted from sunspot AR3664 (which was renamed AR3697 during its second trip around the Sun). A powerful one coronal mass ejection (CME) followed and sent a huge cloud of super-hot solar plasma towards Mars at millions of kilometers per hour.
The consequences of this solar event provided quite a learning experience for scientists who saw it all happen. Researchers at NASA MAVEN orbiter, 2001 Mars Odyssey orbiter, and Curiosity Mars rover each played a key role in collecting data about the event that will help us better understand our neighboring planet and plan future human visits to it.
'We really have the full range of space weather on Mars from May 11 to 20, due to large eruptions, CMEs and outbursts of extremely solar energetic particles, and we have only just started analyzing the data. The May 14 eruption really did go as expected," Ed Thiemann, a heliophysicist at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder, told Space.com in an email.
"The eruption significantly inflated and heated Mars' atmosphere, as expected, and indeed produced the resulting CME auroras Thiemann added.
MAVEN (short for "Mars Atmosphere and Volatile Evolution") had a front row seat for the spectacular display of auroras over Mars. But the way aurorae form in the Martian atmosphere is very different from what happens here on Earth.
The Earth has a magnetic field that protects us from charged particles. This field channels such particles toward the poles, which is why auroras are typically only visible from high latitudes. Mars, on the other hand, lost its magnetic field in ancient times and is therefore not protected against these particles. So when the particles hit Mars' atmosphere, the resulting auroras are widespread across the planet.
Curiosity's Radiation Assessment Detector (RAD) instrument can pick up the most energetic particles all the way to the Red Planet's surface, but it's the less energetic particles that create the stunning auroras. That's where MAVEN's Solar Energetic Particle instrument comes into play, allowing scientists to measure the aurora-creating energy and recreate the event.
"This was the largest solar energetic particle event MAVEN has ever seen," said Christina Lee, MAVEN Space Weather Lead at the University of California, Berkeley's Space Sciences Laboratory, in a recent NASA release. "There have been several solar events in recent weeks, so we saw wave after wave of particles hitting Mars."
Curiosity's RAD instrument also played an important role in gathering information to better educate scientists about how solar storms impact the surface of Mars.
For example, RAD data showed how much radiation the particle storm generated in Curiosity's environment: a dose of about 8,100 micrograms. If anyone had been standing next to the rover at that moment, they would have absorbed the equivalent radiation of 30 chest X-rays! This was the largest increase ever observed in Curiosity's twelve-year lifespan on Mars. To give you an idea of how much solar energy was generated by this event, just look at the black-and-white camera image from a navigation camera on Curiosity (pictured above). There was so much force when the storm hit the surface of Mars that white specks of "snow" were sprinkled across the photo as the charged particles hit the camera!
Meanwhile, when Odyssey encountered the energetic particles in Mars' orbit, its star camera (used to orient the orbiter) took a hit, temporarily knocking it offline. Even with the brief setback, the orbiter was still able to collect details about the charged particles, as well as X-rays and gamma rays with its high-energy neutron detector.
And it's not just technology that can detect this phenomenon through particle explosions; people can do that too.
"The 'spots' and 'streaks' seen in the camera aboard Curiosity are not far removed from what astronauts see when their eyes are bombarded by radiation storm particles. Astronauts aboard the ISS often describe seeing 'fireworks' when they close their eyes during radiation storms," Tamitha Skov, a retired Aerospace Corporation researcher and professor of space weather at Millersville University in Pennsylvania, told Space.com in an email.
"This is because an energetic particle will release energy when it passes right through the CCD sensor in a camera or the retina of the eye, and that deposited energy causes a false signal, causing the camera or eye to mistakenly think it is something sees." a dot or a line of light," Skov added.
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Scientists say that much radiation wouldn't be fatal to humans, but it still serves as a reminder that future visitors to the Red Planet need to be well protected. The information gathered gives us a better understanding of how to keep our Mars astronauts safe in the event of powerful solar storms, researchers say.
"Cliffs or lava tubes would provide an astronaut with additional protection against such an event. In orbit around Mars or in deep space, the dose rate would be significantly higher," said Don Hassler, RAD principal investigator in the Solar System Science and Exploration Division of the Southwest Research Institute. in Boulder, Colorado, said in the same NASA message.
In addition to the safety of people on the Red Planet, scientists are also concerned about agricultural development there. Powerful solar storms like last month's could make it harder to plant and grow enough food in the planet's already challenging environment.
"Since growing plants requires sunlight, energy and a lot of space, it will be difficult to grow enough food in lava tubes or caves, even if the colonists are able to provide enough artificial light to sustain their growth," Skov said. 'Unlike Earth, the atmosphere on Mars is so thin that energetic particles can penetrate all the way to the ground. This means that radiation storms, in one form or another, are an ongoing problem there. They are like a light drizzle that continuously falls on the earth. the surface, all the time."
As sunspot region AR3697 makes its second appearance toward Mars, researchers are looking forward to seeing what else they can learn from this sunspot that just won't quit.
"This same sunspot group is still active this week and is orbiting Mars, and could provide more events that could help us understand the evolution and loss of Mars' atmosphere," Thiemann said.