Sunspot Turning Towards Earth Is so Big It's Changing How the Sun Vibrates

Scientists have detected a sunspot that's so huge it's changing the way our sun vibrates.

Sunspots appear as dark blotches on the sun's surface because they are cooler than the surrounding areas. They form where magnetic fields are particularly strong, driven by the electrically charged gases that constantly swirl inside our nearest star.

Sometimes these magnetic fields can be so intense that they prevent some heat from reaching the surface, forming a sunspot.

Scientists like to keep track of sunspots because due to their intense magnetic fields they are known sources of space weather events such as solar flares and coronal mass ejections (CMEs)—both a type of solar eruption.

The sun
A NASA Solar Dynamics Observatory (SDO) image of the sun, taken September 6, 2022. Sunspots can form on areas of the sun with intense magnetic fields. NASA/SDO/AIA

If flares and CMEs occur in the direction of Earth, they can have effects on our planet including disrupting radio communications and causing electrical problems in power grids. Space weather is also responsible for the shimmering lights known as auroras.

When sunspots occur on the side of the sun facing Earth, scientists can use specially-designed telescopes to see them. However, tracking a sunspot on the back side of the sun requires a different technique.

On Tuesday morning, solar activity news website Spaceweather.com reported: "There are two sunspots on the farside of the sun so large they are affecting the way the sun vibrates."

It added the two sunspots were expected to rotate into view in just a couple of days.

The study of the sun's vibrations is known as helioseismology, and it's a key area of solar science. Helioseismology involves studying sound waves from inside the sun, which can give clues as to what's happening on parts of the sun we can't see.

It's similar to regular seismology here on Earth, in which scientists can work out what's going on inside our planet by studying sound waves that travel through our planet.

The sun is a ball of hot gas, so sound waves travel through its interior very well. Of course, scientists can't hear these sound waves from Earth, but they can detect them by measuring small changes in the light given off by the sun, according to the European Space Agency (ESA).

These changes are measured via the doppler effect, which refers to the increase or decrease in the frequency of light, sound or any other wave as it moves relative to the observer.

While we await information on the two sunspots on the far side of the sun, there are at least three facing us right now that scientists can observe. As of September 5, the biggest appeared to be one known as AR3092, though it's not likely to send any significant flare activity our way.