The sun is about to ‘go blank’ as we hit 'solar minimum', NASA says

Do not be alarmed, but the sun is about to ‘go blank’ – with the dark sunspots which usually speckle the disc vanishing over the next couple of years.

But it’s perfectly normal – part of an 11-year cycle where sunspots regularly fade away, bringing a period of calm.

Sunspots are strongly magnetised and crackle with solar flares – magnetic explosions which bathe Earth in X-rays and UV radiation.

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But over the past couple of years, they’ve been fading – and are sliding towards a low point expected in 2019/20.

‘This is called solar minimum,’ says Dean Pesnell of NASA’s Goddard Space Flight Center in Greenbelt, MD. ‘And it’s a regular part of the sunspot cycle.’

While intense activity such as sunspots and solar flares subside during solar minimum, that doesn’t mean the sun becomes dull. Solar activity simply changes form.

For instance, says Pesnell, ‘during solar minimum we can see the development of long-lived coronal holes.’

Coronal holes are vast regions in the sun’s atmosphere where the sun’s magnetic field opens up and allows streams of solar particles to escape the sun as the fast solar wind.

Pesnell says ‘We see these holes throughout the solar cycle, but during solar minimum, they can last for a long time – six months or more.’

Streams of solar wind flowing from coronal holes can cause space weather effects near Earth when they hit Earth’s magnetic field.