Waco Gem and Mineral Club, Waco, Tx

11.5 Collecting Meteorite Dust

 

11.5: Collecting meteorite dust

Kids who really get into meteorites will itch to collect their own. However, they run into two problems. First, even professional meteorite hunters have a hard time finding and collecting meteorites in the field. They are rare and elusive and hard to identify by scanning the ground. Second, although you can sometimes find small Nantan meteorites from China and little black tektites from Southeast Asia at reasonable prices at gem shows and rock shops, most meteorites are priced, well, out of this world.

What to do to get a meteorite into a kid‘s collection? Think small! A couple of neat web sites provide instructions on how to collect 'micrometeorites' or meteorite dust:

http://www.pbs.org/wgbh/nova/teachers/activities/3111_origins.html

http://starryskies.com/Artshtml/dln/6-00/dust.html

Most meteors burn up in our atmosphere, but as they do, they leave a trail of dust. That dust, along with micrometeorites and other solar debris is constantly raining down. In fact, by some estimates, tens of thousands of tons of extra-terrestrial material falls on earth each year! The web sites I‘ve referenced give instructions on how to collect micrometeorites. Essentially, you need to create a 'Meteorite Trap'. Suggestions include: keeping a bucket under a down-spout during a rainstorm to collect dust in runoff water from a roof; placing a water-filled bucket on a rooftop or other elevated spot for 4 weeks (checking periodically to refill the water as it evaporates); and laying a large plastic sheet (like a shower curtain) in an open spot or at the bottom of a wading pool and collecting residue from the sheet every two days for a little over a week. Another technique involves placing a strong magnet in a paper cup and tapping the cup on the ground around downspouts. Black specks will attach themselves to the bottom of the cup until you remove the magnet and tap them loose over a sheet of white paper. Examine the flecks under a microscope, searching for ones that are spherical and pitted.

With all these techniques, most of what you‘ll collect will be ordinary earthbound dust and dirt. You‘ll need to collect, concentrate, and dry the residue, sort out the dead insects, leaves, and other big things, and then use magnets to separate potential meteorite dust from earth dust. Viewed under a microscope, meteorite dust is often rounded and may have small surface pits. Perhaps the most amusing or quirky incidence regarding meteorite dust comes from Norway, where Ragnar Martinsen, sitting in the outhouse of his cabin, heard an explosion and later found tiny grains of rock in aluminum pans he had left in his yard. Scientists reported these to be pieces of only the 14th recorded meteorite landing in Norway.

At best, you‘re not likely to get more than a few pieces the size of a sand grain or smaller, but a meteorite is a meteorite, and how many people can claim to have collected one on their own? This fun activity also vividly illustrates how the earth we‘re on is part of the larger universe, floating through space with cosmic debris that sometimes pays a visit.

Note: Kids can use this activity toward satisfying requirements for the Collecting badge simultaneously (Activity 5.1).