How Does the Sunspot Cycle Affect Earth?
ES2605  Spots on the Sun
Long before the invention of the telescope, ancient people noticed that the sun is not a perfect, featureless disc. During dust storms and on overcast days when most of the sun's rays were blocked, they noticed that the sun's surface was occasionally marked with dark spots. They even noticed that these spots moved across the face of the sun over a period of several days. Soon after the invention of the telescope, astronomers of the 17th century used their new tool to study and map sunspots in detail.
Yohkoh and Big Bear Solar Observatory

This movie was made from daily images of the sun taken over several days. It shows the sun as it appears in visible light - rather plain looking, except for a few dark sunspots.

Sunspots are interesting to look at, but let's face it— they're 150 million km (93 million miles) away from Earth. How could they possibly affect us?

  !   Move your cursor over the sun in the image to see how the sun would look if your eyes could see the sun's x-ray radiation.

1. Why do sunspots move across the face of the sun?

2. What do the sunspot regions look like in the x-ray images? How might the activity at these areas affect Earth?

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