The northern lights may be visible across parts of the US this weekend. Why are they so active right now?

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A series of solar flares and coronal mass ejections from the sun could create dazzling auroras that could be seen as far south as Alabama and Northern California but disrupt communications on Earth tonight and over the weekend, according to the National Oceanic and Atmospheric. Administration’s Space Weather Prediction Center.

The center, which is a division of the National Weather Service, issued a geomagnetic storm watch for Friday evening. This is the first watch of its kind to be released since January 2005.

As the sun approaches peak activity in its 11-year cycle, known as solar maximum, later this year, researchers have observed increasingly intense solar flares erupting from the fiery orbit.

The increased activity of the sun causes auroras that dance around the Earth’s poles, known as the northern lights, or aurora borealis, and southern lights, or aurora australis. 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 light in the sky.

The Space Weather Prediction Center tracked multiple strong flares emitting from a large sunspot cluster on the sun’s surface since Wednesday. The cluster is 16 times the diameter of the Earth.

Scientists have observed at least five coronal mass ejections, or large clouds of ionized gas called plasma and magnetic fields that erupt from the sun’s outer atmosphere, shooting from the sun toward Earth. These significant outflows are expected to arrive as early as midday on Friday and continue into Sunday.

The peak of geomagnetic storm activity for Earth will be between 2 a.m. and 5 a.m. ET on Saturday, according to the center’s forecast.

The center referred to this as an “extraordinary event”.

Geomagnetic storms driven by the sun in recent months have seen auroras in places where they are rarely seen, including as far south as New Mexico, Missouri, North Carolina and California in the United States , and south-east England and elsewhere. of the United Kingdom.

Depending on the location, the auroras may not always be visible overhead, but keep an eye on the sky, experts say, because they can create a colorful display there as well.

The aurora borealis can be seen in the northern horizon in the night sky above Wolf Lake in Minnesota's Cloquet State Forest in September 2019. - Alex Kormann/Star Tribune/Getty Images

The aurora borealis can be seen in the northern horizon in the night sky above Wolf Lake in Minnesota’s Cloquet State Forest in September 2019. – Alex Kormann/Star Tribune/Getty Images

Effects of geomagnetic storms

When directed at Earth, these hearings can be caused by geomagnetic storms, or large disturbances in the Earth’s magnetic field.

“Geomagnetic storms can affect infrastructure in near-Earth orbit and on the Earth’s surface, potentially disrupting communications, the electrical power grid, navigation, radio and satellite operations,” of according to the Space Weather Prediction Center. “(The center) has notified the operators of these systems so they can take protective action.”

Solar storms generated by the sun can cause radio blackouts and even endanger crewed space missions.

The center warned that additional solar activity could cause geomagnetic stormy conditions to persist through the weekend.

So far, researchers have observed only three severe geomagnetic storms during the current solar cycle, which began in December 2019, according to the center.

Previously, a G5, or large geomagnetic storm, occurred on October 23, which caused a power outage in Sweden and damaged power transformers in South Africa, according to the center.

Space weather tracking

Every 11 years or so, the sun experiences periods of low and high solar activity, related to the amount of sunspots on its surface. The sun’s strong and ever-shifting magnetic fields drive these dark regions, some of which can reach the size of Earth or larger.

During a solar cycle, the sun will transition from a calm period to an intense and active period. During peak activity, known as solar maximum, the sun’s magnetic poles flip. Then, the sun will grow quiet again during a solar minimum.

The solar eclipse is expected to peak in mid-to-late 2024, but the sun will remain active for a few years after that.

Teams at the Space Weather Prediction Center use data from ground and space-based observatories, magnetic maps of the sun’s surface, and ultraviolet observations of the sun’s outer atmosphere to determine when the sun is most likely to launch solar flares, coronal mass ejections and space weather another that could affect the Earth.

Solar flares can affect communications and GPS almost immediately because they affect the Earth’s ionosphere, or part of the upper atmosphere.

Energetic particles emitted by the sun can also disrupt electronics on spacecraft and affect unprotected astronauts within 20 minutes to several hours.

The material sent hurtling from the sun during coronal mass ejections can reach Earth 30 to 72 hours later, causing geomagnetic storms that disrupt satellites and create electrical currents in the traveling upper atmosphere through the ground and can affect electrical power. grids.

The storms also affect the flight patterns of commercial airlines, which are instructed to stay away from the Earth’s poles during geomagnetic storms due to loss of communication or navigation capabilities.

Extreme storms have occurred before, such as one that knocked out the power grid in Quebec in 1989 and the Carrington Event in 1859. The latter remains the most intense geomagnetic storm ever recorded, causing telegraph stations to spark and catch fire.

If such an event were to occur today, it could cause trillions of dollars in damage and could bring down several power grids for a significant amount of time.

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