aurora borealis

Earlier in May, the night sky across North America was filled with amazing colors. Bright purple, pink, red, and green light shone brightly.

The aurora borealis!

These natural light shows are usually seen in places close to the North Pole—like Northern Canada and Alaska, which is why they are sometimes called the northern lights.

May 10th 2024

But the weekend of May 10th was different.

People living in California and other southern states like Arizona and Alabama were all able to catch a glimpse of this phenomenon because the lights appeared much farther south than normal—causing a lot of excitement, and resulting in some amazing photos!

solar storms

magnetic field

An aurora is caused by high levels of activity on the Sun's surface, called Solar Storms. These send large amounts of charged particles, mainly protons and electrons, out into space, including toward Earth. As they get closer to Earth’s atmosphere, the Earth’s magnetic field deflects the particles to areas around the North and South Poles.

Here, when the particles interact with different gases in the atmosphere, different colors of light are created. Interactions with oxygen cause green light to appear, whilst nitrogen creates pinks and blues—and when they all appear together, the colors are spectacular!

geomagnetic storm

When huge amounts of particles reach Earth’s atmosphere, they can cause what’s known as a geomagnetic storm, with the aurora being the part of the storm that we can see. But while it’s an amazing sight, the geomagnetic storm can disrupt communication systems like GPS and even the electricity grid. So, just like weather forecasters predict thunderstorms, space weather forecasters predict how powerful geomagnetic storms might be. Then they alert the companies that provide the services we use, so they can be prepared.  

For the recent storms, a team of forecasters observed this activity on the Sun over two days before the aurora borealis were seen on Earth. They could see a lot of solar activity, and as a result, forecasted a “severe” grade 4 geomagnetic storm, but when the storm occurred, the team increased its grading to an “extreme” level 5 storm—the highest possible grade! 

It was the first storm to be given this grade in over 20 years, but thankfully there was very little impact on communication systems. However, the extreme level of the storm does explain why people who wouldn't normally see the northern lights were able to.  

Both in America, and around the world.

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