Unveiling Stardust on Your Rooftop: a Magnetic Microparticle Sorter and Spotter

"If dinosaurs had a space program, they would not be extinct"

-Carl Sagan

Major meteor shower events, the Perseids, in the middle of August, and the Geminids and Quadrantids, in December and January, are getting closer (you can find a calendar here), so you better get your meteorite-catching equipment ready!

What's that? You don't have any?! Well, it is good that you stumbled upon this instructable to get your own Micromeoterite Separator and Spotter (MSS).

Of course, if you are lucky to get a carbonaceous chondrite landing in front of your door, you do not need it, but there is still a good chance that a speck of a falling star is waiting to be discovered on your roof. You can find many web site and YouTube videos telling the story of work of love and patience. The meteorites you are looking for are microscopic, and searching for them requires focusing on those that are easier to separate from the terrestrial dust garbage.

However, a strong magnet will help with this task if we look to only metallic ones. Still, the quest wasn't easy, but discovering one would bring all the rewards.

In this Instructable, we propose a simple device to help this discovery journey. As in our previous instructable, we tried to keep it small as we love microscopes.

• A 3D PRINTER.
• 2 MICROSCOPE GLASS SLIDES. We have used slides of 75x25x1.4 mm.
• 1 SMALLER MICROSCOPE GLASS SLIDE. We have used slides of 75x21x1.4 mm.
• NEODYMIUM MAGNETS: we have used a set of 1 cm diameters.
• A USB MIcroscope. We have used an inexpensive Chinese one with a claimed magnification range of 50-1000x and a camera resolution of 5M pixels. However, a stereomicroscope is also an excellent option.

The MSS consists of a plastic 3D printed frame with two partitions and a transparent floor and roof separated but a short distance to attract magnetic dust to the roof using a strong magnet and move it to a collecting partition.

ASSEMBLY INSTRUCTIONS

• 3D print the STL file containing the MSS frame shown in Figure 1. The frame size has been calculated for slides with a standard size of 75x25x1.4 mm.
• Cut a metalized paper card surface to have the exact size of the slide. We have used one obtained from chocolate packaging.
• Add the bottom slide to the bottom of the frame, fitting the slide to the guide of the frame. Use gloves and be careful not to force the slide to avoid cutting yourself if it breaks. Add the aluminated slide on the bottom and stick both with some tape to keep them firm. The mirrored surface will help see the material attracted by the magnet.
• Add the slide on the top of the frame. This slide should be able to slide as shown in Figure 2.
• Add the smaller slide using the later slit. We have used a small 61x16x1.4 mm slide usually provided in educational microscopes. This slide will remove good specimens for further microscopic analysis and collection.

Finding micrometeorites is a dirty business. You should find a lofty, relatively undisturbed place where dust, possibly only from space, can accumulate. A flat roof will be perfect, as micrometeorites can stay in place after falling on it and be easily picked up. We, however, could only choose a dry-out rain gutter where sediment has accumulated from trickling down the roof. It would be best to use a strong neodymium magnet in a plastic bag to collect as much dust as possible (see Figure and video for the procedure). Try collecting from different places to increase that chance as much as possible. Plenty of videos and websites dedicated to this topic illustrate the collection process.

First, put your dust in the larger partition until it is below the barrier. Then, place your glass slide in the grooves in the MSS and place the magnet above the dust. You should see some dust accumulating on the glass on the bottom of the magnet.

Then slowly move the dust to the smaller container and release it.

Repeat this a few times until you have a sizeable pile of dust in the smaller container. You might want to shake the dust carefully in the large container to remove some iron from the bottom.

Now it is time to test your patience and luck find! You can use a handheld or an ordinary stereo microscope to scan the sieved-out dust meticulously. Micrometeorites are usually spherical as it was shaped in this form, as by entering the Earth's atmosphere at high speed, it partially melts. However, they can also have other shapes. An excellent book on this topic is given as a reference, and many youtube videos and specialized websites help you with this citizen scientist hobby (see References).

Finding micrometeorites is challenging, and it requires a lot of patience. We have started to give a try to our device collecting some dust from the house room and gutter pipe but so far, with little success. A lot of the metallic material comes from fireworks specks of dust or the material in the roof tiles (see pictures).

However, we won't give up, as when this happens, you will be rewarded by the incredible consideration that the tiny rock that you have found came from space, dwelling for billions of years on a comet and standing harshly, entering the Earth's atmosphere, and finally landing on the roof of your house to tell the story of its journey.

And who knows, you might even find on its surface the little Prince of de Saint-Exupéry waving back at you :-)

REFERENCES

• Larsen, J., 2017. In search of stardust: amazing micrometeorites and their terrestrial imposters. Voyageur Press (MN).
• Larsen, J., 2019. On the trail of Stardust: The guide to finding micrometeorites: Tools, techniques, and identification. Voyageur Press.

In this instructable, we have presented a simple and easy-to-build device that might help to isolate metallic dust for microscopic analysis. The idea behind the device is to search metallic micrometeorites, but it is up to you to find other possible use.

Thank you for reading our project, and if you like it, please do not forget to add your thumb-up of appreciation!