Kid Experiment: Finding Meteorite Dust with Magnets

Adults will be amazed at this experiment, too.

Two of the major components of asteroid-pieces-become-meteorites are iron and nickel, both magnetic metals.

These asteroid pieces crash into Earth all of the time -- thousands every day.

As they crash into Earth's atmosphere, they heat-up, melt and vaporize.

Years ago, as I was lying on my lawn late at night, stargazing through my binoculars, I accidentally caught one of these in my lens perfectly, directly above me. I saw it light up, leave a trail of sparks, and I even heard it go "phzzzzzzzzzzzt," a second or two later (indicating a terminal altitude of only 1,000 to 2,000 feet).

When the asteroid-pieces-become-meteorites vaporize, the hot iron gas or hot nickel gas quickly cools, and recondenses into little spheres, or "spherules," of each metal.

These metal spherules are so tiny that they float in the air, like dust. We are constantly subject to a rain of these particles, and even breathe them in, so that our lung tissues are very lightly coated in them.

Because the asteroid metal spherules are constantly raining down everywhere, our gardens outside are dusted with them.

The spherules can easily be recovered and "collected" as follows...

Materials: A white paper plate, a small but powerful magnet, a clear plastic bag fitting easily over the entire hand, access to a garden with dry ground.

Directions: Grasp the magnet between the thumb and index finger, and pull the plastic bag over that hand so that the entire hand is covered up to the wrist. Go outside and, without digging-up or disturbing the dry soil of the garden in any way, gently dab the dry soil with the part of the plastic bag covering the magnet. You will see odd-shaped chunks of debris adhering to the bag, as well as a fine dust. Much of the dust is comprised of iron and nickel spherules.

Hold the debris-and-dust-coated section of the plastic bag directly over the paper plate, debris side down, and without removing the plastic bag from the hand carefully pull the plastic bag away from the magnet inside the plastic bag so that the debris and dust shower onto the paper plate.

Repeat this process again and again, until there is a respectable collection of debris and dust on the plate.

If you move the magnet under the plate you can separate the magnetic debris and dust from the dirt.

If you look closely, you can watch the spherules roll down the plate when it is tilted.

If you have access to a microscope, you can actually see the meteorite spherules which you have gathered up close.

Impact Craters on Earth

Most people think that that meteor crater in Arizona, Barringer Crater, is a "one time thing," though that is not ay all the case.




In a sense, the answer to the question, "Has the Earth been hit with meteors frequently?" is in the sky, above your head, on the surface of the Moon.



Essentially, the Earth would have been bombarded with the same array of "cosmic cannon fire" -- meteorites, asteroids, and comets -- as the Moon.



There would be some difference because of the atmosphere. Meteorites smaller than a certain size frequently don't make it down to ground level, in Earth's case, because unlike the Moon the Earth has an atmosphere, and friction, when they slam into the atmosphere, heats them, melts them and vaporizes them.


But there would also be a difference arising from the fact that the Earth is much larger than the Moon. Our gravity, about 6 times that of the Moon, attracts a lot more naturally-occurring "space junk," and therefore many more impacts.



The main reason why the Earth does not look like the Moon is because our atmosphere and the life forms it supports quickly fills in craters with deposits which masks their existence. Earth would look like the Moon were it not for our atmosphere.



Despite the healing effects of Earth's atmosphere, many impact craters are still visible all over the Earth.



Before Barringer Crater was formed by a 20 megaton impact about 49,000 years ago, a meterorite slammed into Wolf Creek, Australia, around 300,000 B.C.




A large piece of rock slammed into Bosumtwi, Ghana, around 1,000,000 years ago with an enormous impact of 7,000 megatons.




The Manicougan, Quebec crater, generated by an impact about 214,ooo,ooo years ago, has a substantial deposit of rebound material in the center of it, after the meteorite slammed into the Earth and buried itself there.




The Brent, Ontaria crater was genetated by a 250 megaton impact about 400,000,000 years ago.



Many other impact craters on Earth have been photographed from space.