A massive “hole” on the surface of the Sun could send solar winds hurtling toward Earth at speeds of 2.9 million km/h.
The sunspot with a diameter 18 to 20 times that of Earth has appeared on the Sun. Photo: NASA/Solar Dynamics Observatory.
This new hole has appeared after a previous sunspot, which was about 30 times the size of Earth, started rotating away from Earth, and the new coronal hole, approximately 18-20 times the size of Earth, emerged, as reported by Business Insider on March 27.
In soft X-ray and extreme ultraviolet (EUV) images, coronal holes appear as dark regions within the Sun’s corona (the outermost layer of the Sun’s atmosphere). They appear dark because they are cooler and less dense than the surrounding plasma, while also having an open magnetic field, a unipolar one. This open magnetic field structure allows solar wind to escape more easily, creating fast solar winds, often referred to as high-speed streams when analyzing structures in interplanetary space.
Coronal holes can send solar winds into space, potentially causing damage to satellites and triggering spectacular auroras if they reach Earth. Scientists are not concerned about the new hole damaging infrastructure, but it may contribute to auroras appearing in some parts of the world.
Coronal holes are relatively common but tend to appear near the Sun’s poles. According to Mathew Owens, a professor of space physics at the University of Reading, as the Sun approaches its maximum in the 11-year activity cycle, these holes are more likely to appear near the Sun’s equator.
“This hole is at the equator, meaning we are almost certain to see some high-speed winds heading towards Earth a few days after the hole rotates past the central meridian,” Owens said.
Solar winds can blow very fast, exceeding 800 km/s or 2.9 million km/h, according to Daniel Verscharen, an associate professor of climate and space physics at University College London.
“The shape of this coronal hole isn’t particularly unique. However, its position makes it quite interesting. I predict that some fast winds from that coronal hole will arrive at Earth around late Friday to early Saturday this week,” Verscharen said.