Magnetometers are used to measure the direction of a magnetic field or the magnetization of a magnetic material. They can also be used to measure geomagnetic storms. So, if you missed the aurora sightings from the latest geomagnetic storm you can predict the next ones with your own DIY magnetometer.

Supplies:

  • Plastic bottle
  • Clear tape
  • Index card
  • Laser pointer
  • Super glue
  • Plastic straw
  • Sand or stones
  • Scissors
  • Small bar magnet
  • Small craft mirror
  • String

Directions:

  1. Remove the top part of the plastic bottle using scissors and fill the bottom of the bottle with sand or stones. The sand will make sure it won’t fall over.
  2. Cut the index card so it will fit inside the bottle without touching the sides. Once the card is cut to the right size, use super glue to attach the longer side of the bar magnet to the rectangular card. Center the magnet along the top of the card.
  3. Use the drinking straw to suspend the magnet in the bottle by cutting it to fit along the top of the bar magnet. Glue the straw to the top of the magnet. Once the glue is dry, thread a length of string through the straw. The string should form a triangle shape at the top of the magnet.
  4. Glue the small mirror to the magnet on the opposite side of the card. Align the mirror with the thread at the point of the triangle to make sure the magnet hangs horizontally.
  5. Make a small hole in the bottle cap and thread the string through it. Reattach the bottle cap to the top part of the bottle. Then, tape the top part of the bottle back onto the bottom part so the magnet contraption remains inside the bottle.
  6. Adjust the string so the card hangs freely above the sand and below the cut line in the bottle. Secure the string.
Now, to use your magnetometer you need to use the laser pointer and direct the light at the mirror. If you keep the laser pointer in the same position, you can track the movement of the magnet by marking for changes every few hours. The magnet will move with the Earth’s magnetic field. When there is a geomagnetic storm, you should see more movement than usual. You may even be able to predict when there will be an aurora sighting!