The Northern Lights, also known as the Aurora Borealis, is a natural light phenomenon caused by the solar wind. … [+]
A head-on “interplanetary impact” that strikes Earth’s magnetic field is something scientists need to anticipate to protect any infrastructure that conducts electricity, according to a new study. Published Today is The forefront of astronomy and space science.
Spectacular displays of green, red, purple and blue auroras, such as the global geomagnetic storm on May 10, could mean powerful electrical currents could reach Earth and cause damage to power lines, oil and gas pipelines, railways and undersea cables.
Interplanetary impact
The interplanetary shock waves that cause the beautiful aurora borealis and southern lights are actually disturbances in the solar wind caused by coronal mass ejections from the Sun. CMEs are clouds of magnetic and charged particles from the Sun that travel into space at speeds of up to 1,900 miles (3,000 kilometers) per second.
These disturbances compress Earth’s protective magnetic bubble, which often produces the auroras, but the study suggests that the angle at which the interplanetary shock wave strikes is key to the flow’s strength.
This is important because interplanetary shock waves are far more common during the solar maximum that scientists believe is happening now.
Geomagnetically induced currents can damage infrastructure that conducts electricity. The more powerful the interplanetary impact, the more powerful the currents and auroras. If scientists could predict whether an interplanetary impact would be a head-on strike rather than a graze, it could help protect infrastructure before the impact, the researchers say.
The magnetosphere or magnetic field around the Earth.
Higher Peaks
The paper found that head-on impacts on the Earth induce the strongest geomagnetically induced currents, rather than those that strike the Earth at an angle. Using a database of interplanetary impacts and cross-referencing it with measurements of geomagnetically induced currents from a natural gas pipeline in Mantsala, Finland (the “aurora belt”), the scientists found that head-on impacts increase the peak value of geomagnetically induced currents because they compress the magnetic field more.
They also found that the strongest peaks occur near “magnetic midnight,” the nighttime period on the Earth’s night side when the North Pole is between the Sun and Mantzara (around actual midnight local time).
Space Weather
“Auroras and geomagnetically induced currents are caused by similar space weather factors.” Said Lead author Dr. Denny Oliveira of NASA’s Goddard Space Flight Center. Space weather refers to the stream of charged particles that originate from the sun, known as the solar wind. “The aurora is a visual warning that these currents in space can generate geomagnetically induced currents on the ground.”
The aurora on May 10 was particularly intense. The aurora usually appears in an oval shape around the poles, but on this day the oval expanded due to the arrival of multiple CMEs. “The auroral field can expand significantly during a severe geomagnetic storm,” Oliveira said. “Usually its southern boundary is around 70 degrees latitude, but in extreme cases it can go down to 40 degrees or even more. This certainly happened during the May 2024 storm, the most intense storm in the last 20 years.”
May the clear skies and big eyes be with you.
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