Safely observe solar activity

Some solar activity can be observed using a pinhole projector, and I will explain how to make one in this post. It is important to note that a pinhole projector lacks great resolution, and therefore cannot be used to observe certain phenomena. Again, never look directly at the sun. 

Shoe boxes or tubes are typically used when making a pinhole projector. I used a shoebox because it allows easy access while constructing the pinhole. Keep in mind that the further the light travels through the hole to the backdrop, the larger the image will be, but if the box or tube is too long, the image might be too blurry.

On one END of the box or tube, cut out a small square, and tape a slightly larger piece of aluminum foil over the hole, making sure to seal any gaps with opaque tape. Then poke a tiny pinhole through the foil. Near the other end of the box on the SIDE, cut out a viewing hole. (Make sure you do not cut a hole in the other END of the box.) And, of course, put the lid back on if using a shoebox. You can seal the lid as well, if you like.

While using your pinhole projector, be careful not to look at the sun! In order to align your projector, simply face your shadow and point the pinhole side of the box or tube in the general direction of the sun over your shoulder. Use the shadow of the projector to line it up with the sun and then look inside your viewing hole at the image of the sun!

My boyfriend took this picture through the viewing hole of my projector during a solar eclipse last spring.

As you can see, there are two images of the solar eclipse being projected. Why do you think that is?

I have heard that this method can be used to view sunspots, but I don't believe that is possible. During the Venus transit last year, I was not able to view it using my pinhole projector, because the shadow cast by Venus was much too small. However, there is another popular technique that supposedly works. Using solar filters on binoculars, you can project the image of the sun onto a white background, but be careful! Paper and other materials can catch on fire if you do this for too long! Of course, never look directly at the sun. ScienceDaily.com recommends: "To help block out extra sunlight, cut holes in card stock and fit it over the lenses." Spotting Sun Spots

Also, if you have a telescope and a solar filter, you can view sunspots directly or project the image onto white computer paper, and if you really want to be fancy, you can build a sun funnel!

Michael A. Seeds' Foundations of Astronomy tells us that sunspots are evidence of the sun's great magnetic fields. Like Earth, the sun has north and south magnetic poles, and like Earth, the sun's poles switch. However, while Earth's polar flips seem to be sporadic, the sun has an 11-year "magnetic cycle" in which the poles reverse their magnetic direction. There are a few models which try to explain the sunspot cycle, but we still do not know why this magnetic activity occurs. The magnetic activity of the sun is extremely interesting to me. Let me know if you would like to hear more about it.

I have yet to try observing sunspots, but if you have or try it out, let me know what you did and your results!