Seeing Spots!

Science World, Jan 11, 1999

During solar max, When the sun's magnetic activity is at peak, numerous sunspots appear on the sun-'s surface. Make this "sunspot viewer" to get a good (and safe) view of the dark spots on a sunny day. (Never look directly at the sun!)

You need:

hole puncher * two 3x5 index cards * table * mirror * clay * tape * paper * ruler * a room with a door or window to the outside

To do:

1. Punch a hole in an index card as shown in the diagram. Tape a second card under the hole.

2. Look for a place outdoors to set up your sunspot viewer. It must be near an open window or door and in direct sunlight. (You'll need to reflect sunlight through the window and onto a wall inside the building.)

3. Set up a table about 60 feet from the wall inside the building (see diagram).

4. Put a lump of clay on the table. Stand the mirror in it.

5. Hold the index card about three inches in front of the mirror's center.

6. Adjust the angle of the mirror and the position of the card. Sunlight should reflect off the mirror, through the hole, and into the building.

7. Ask a friend to look for a bright circle on the wall indoors. (The darker the room, the brighter the circle.) That circle is an image of the sun!

8. Tape a piece of paper on the wall, over the image. Use a pencil to trace the image. Do you see sunspots (small, dark dots)? If so, draw them in.

Conclusions:

What do you notice about the sun's image on the paper? Why do you think the sun's image moves fast?

Don't Stop Now!

Track sunspot activity by repeating the activity once a week for several weeks. Use a different sheet of paper each time to record the number of sunspots you observe.