Sunday, August 28, 2011
Here is a particularly pretty area. The pointer is pointing to a round micrometeorite candidate. It's stuck to some probably earth-origin stuff--the hard drive magnet magnetized all the samples, so they stick together. There is also a pretty piece of glass or crystal closer to the top edge.
I ended up perfecting a method for extracting them. First, I use the toothpick to sweep the area around it clean, looking in the microscope most of the time. It's confusing, since the miscroscope reverses the view, but eventually the brain gets used to it. Then I wet the toothpick with acetone. The micrometeorite candidate sticks to the toothpick. I then transfer it to a clean piece of glass. Because the acetone evaporates so quickly, it's easy to just wipe the toothpick on the glass and the micrometeorite drops off. I lost two promising samples--especially that nice big round one in the first photo--before I got the above two.
If you try to view this with bright-field microscopy, of course you just get black silhouettes. What I did is I taped a bright LED flashlight to the microscope, pointing at the sample, and then I took timed exposures, holding the camera to the eyepiece (sometimes with some sort of adapter to keep the camera in place). For the second two photos, I found a way of adding more light. I took the microscope outdoors, and then reflected sunlight onto the slide with a mirror (actually, a hard drive platter--they make lovely mirrors).
The photos were taken with point and shoot cameras hand-held to microscope eyepieces, with some loose-fitting adapters to make it easier. The first photo was with a Sony P100 through the 10X Huygens eyepiece that the microscope came with. The second and third photos were with a Canon G7 through a Rini 30mm telescope eyepiece, using my home-made telescope-to-microscope eyepiece adapter.
Update: I wish I knew how to better identify micrometeorites. The very round one may not be one--see this article.