There is nothing new under the Sun, the Bible tells us. It is practically a byword for reliability.
But there is plenty that is new on the Sun. That giant roiling mass of unbelievably hot gases does more than just keep the weather going. In particular, the periodic appearances of sunspots and solar flares have several minor but irritating effects. They have also led more creative theorists to speculate about dramatic impacts.
You don’t have to be a rocket scientist to understand sunspots and their close companions, solar flares, but it probably helps, which is why we’ve taken our definition of the phenomena from Nasa: “Sunspots are areas that appear dark on the surface of the Sun. They appear dark because they are cooler than other parts of the Sun’s surface. Solar flares are a sudden explosion of energy caused by tangling, crossing or reorganising of magnetic field lines near sunspots”.
They are effectively storms on the Sun’s surface, which occasionally send huge plumes of solar gases into the atmosphere.
There are records of sunspot observations dating back nearly 3000 years. They were first seen through a telescope in 1610 by English astronomer Thomas Harriot. His contemporary Galileo Galilei published his Letters on Sunspots two years later. Hitherto the Sun was believed to be unchanging and constant.
Studies of sunspots contributed to undermining a traditionalist view of the universe and encouraging scientific exploration. About 200 years after, German astronomer Samuel Heinrich Schwabe demonstrated that they occur in roughly 10-yearly cycles.
Sunspots have turned up in the news in recent weeks with the appearance of a new sunspot region. The new sunspot region sent two solar flares into space in a period of a few hours on May 2. It’s been dubbed AR3663, a less than poetic name. We’re guessing it may have been dreamt up by a solar panel.
Sunspots and solar flares are usually benign but that hasn’t stopped people speculating that they can have dramatic effects on Earth. As the recent flares were aimed in our direction, they had the capacity, according to space.com to “wreak havoc with power grids, telecommunication networks and orbiting satellites, as well as expose astronauts to dangerous doses of radiation”.
But they didn’t. Even though the activity on May 2 was the most powerful kind of flare, the X-Class, its less than spectacular effects included interfering with shortwave radio broadcasts in Australia, China and Japan.
As we know all too well, any usual activity beyond our planet is likely to attract the attention of space cadets. Sunspots and solar flares are no exception.
One of the most imaginative students of their effects was Soviet scientist Alexander Chizhevsky, founder of heliobology – the study of the Sun’s effect on biology. His research led him to believe that sunspots directly affected human behaviour in powerful and dramatic ways. He recorded sunspot cycles then tried to line them up with historical events, such as wars and revolutions. Close inspection revealed his figures didn’t add up and even if they had, what was one supposed to do with the information? Keep one’s army inside during periods of increased solar activity?
Marginally more plausible – on the face of it – suggestions that there is a link between sunspots and things here on the ground have been made around global warming. After all, that’s the sun’s main job – warming the globe.
But on closer examination this, too, turns out to be incorrect. The Sun’s effect on temperatures does indeed fluctuate but the variation is trivial compared to that caused by human activity. In fact, volcanic eruptions have more impact on temperatures.
Meanwhile, in other Sun-related news this week, the European Space Agency’s Solar Orbiter probe has shed some new light on old Sol. Its latest close-up views of the Sun have revealed that our neighbourhood star has a “fluffy corona”.
The fluffiness occurs in the border between its lower atmosphere and outer corona. The images were captured by the Extreme Ultraviolet Imager instrument on the Solar Orbiter and can be viewed on the ESA website. At the time the images were captured, the ESA said, the spacecraft was at roughly one-third of the Earth’s distance from the Sun, heading for a closest approach of 43 million kilometres. That might not sound very close, but at that distance anyone should be able to see its spots.
