Why are scientists monitoring an Earth-size spot on the surface of the Sun?

In August, scientists detected a spot on the surface of the Sun, rapidly growing to be the same size as the Earth. What is it? Is it dangerous for the Earth?

Image: Unsplash/Javid Naderi

The sunspot was there before; however, it was barely visible. In August 2022, scientists reported that it had grown to 10-times its original size in just a couple of days, giving place to two spots with cores the size of the Earth. Tony Phillips, a retired astronomer with NASA, also warned that “extreme storms can be expected” on SpaceWeather.com.

Image: Two sunspots in 2016, NASA.

The sunspot was named Active Region 3085 or AR3085.

Image: Unsplash/Brano

Sunspots are dark surface areas that are cooler than their surroundings, as shown in the image. Their cooler temperature is only relative, as they can reach up to 3,700ºC/6692ºF, next to the 5,000ºC/9032ºF of the surrounding areas.

Image: NASA

AR3085 can erupt solar flares that produce high-energy particles that could affect the atmosphere.

Scientists pay close attention to spots that are directly facing the Earth. Robert Cameron, an expert at Max Planck Society, told Deutsche Welle that the high-energy particles “could affect people in space and damage electrical infrastructure on the ground.”

These radiation and solar wind storms are called Coronal Mass Ejections (CME). In the event of a CME, high-energy particles could also impact satellites.

Coronal Mass Ejections are massive explosions that send solar plasma and magnetic flux away from the Sun and into interplanetary space. The magnetic flux causes geomagnetic storms that can damage communication systems when hitting the Earth’s atmosphere.

Image: NASA

CMEs are frequent when the sun's surface is most active. This activity varies according to the solar cycle, which usually lasts around 11 years.

Image: NASA

In September 2020, NASA confirmed that we are in the 25th Solar Cycle. It started in December 2019.

Image: Unsplash/Andrey Grinkevich

Scientists can predict the next period of high activity in a solar cycle, called Solar Maximum. The estimated date for this would be between November 2024 and March 2026. The Solar Maximum is determined using the number and intensity of sunspots.

Image: Unsplash/Nishaan Ahmed

During the Solar Minimum, when the Sun has low activity, Coronal Mass Ejections are rare. They can add up to one per week. During the solar maximum Coronal Mass Ejections happen daily and can be observed frequently.

Aurorae are another consequence of Coronal Mass Ejections. These Polar lights are natural lights displayed in the night sky, predominantly visible in high-latitude regions.

The aurorae are such a beautiful visual spectacle that many tourists plan their vacations to enjoy this phenomenon first-hand.

Despite having drawn the attention of the world's scientific community, these sunspots don't seem to pose a risk to Earth. The maximum effect during the period of low activity could be a short shutdown of radio frequencies.

Image: NASA

NASA and other space agencies have round-the-clock surveillance systems watching the Sun. Scientists observe the surface and atmosphere of the Sun through satellites and even have special instruments to study its core.

Image: NASA

The Sun is the largest object in the Solar System. So big that 1.3 million Earths would be necessary to fill its volume, according to NASA.

Image: Unsplash/Bryan Goff

Even if they can appear as a threat, sunspots and CMEs are a part of the natural order of our universe. The sun's magnetic field and gravity keep the Solar System together, from the planets to the small debris.