Solar activity and northern lights

Solar activity

Remember: Never look directly at the sun!
The sun is our closest star and the source of heat on the Earth. What happens to the sun affects us living on Earth to a large extent. In this activity, we will see that the sun is an active star and how we can notice the activity on the sun here on Earth.

You will need

Computer with internet access
Registration form for the number of sun spots (in Norwegian)



The sun is not a perfectly smooth yellow slice. Sometimes we can see spots on it. Sunspots are areas on the sun with great activity. The more sunspots, the more active the sun is. From pictures of the sun you can count the number of sun spots.

Every day, photos of the sun are taken with SOHO spacecrafts. On you can find today's image of the sun. Click on the image of the sun to make it bigger.

Solar wind and the northern lights

The light does not come only from the sun, there are also small particles which are being ejected. When the sun is active (many sunspots) there are many particles. This particle flow is called solar wind. Since the sun is far away from the Earth and the particles have a lot less speed than the light, it takes about 3 days before the solar wind reaches the ground.

bildeAround the earth, there is a magnetic field and it gets disturbed when the wind hits. Earth's magnetic field is measured, among other things, at the University of Tromsø. Here you can find the latest measurements by selecting a month and year. The blue curve shows how much the magnetic field is disturbed.

When the solar wind hits the magnetic field, some of the particles are also captured. These particles flow down to the magnetic poles on the ground. The northern lights occur when the particles from the solar wind collide with the Earth's atmosphere.


Visit and count how many sunspots there are, several days throughout a month. Check how big the disturbances in the magnetic field are a few days after each sun drop.
Write the observations in the registration form.

Are you ready to find any connection between sunspots on the sun and the magnetic field on Earth? It is wise to draw a curve for the sun and one for the Earth. Your teacher can help you with that.

Enter the data you found for the northern lights on the internet.

Good luck!

Northern lights
Facts about the northern lights
Mythology and superstition
Observing the northern lights
Photographing the northern lights