When a meteor hits the atmosphere, it does so at typically speeds of 70 miles per second. While not relativistic (that is, comparable to the speed of light – 186,280 mps-ish) it is still pretty fast.
When this happens a lot of heat is generated. The object will typically be metallic. It’ll melt the rock, and it will shed particles. Those particles will fall to earth as a micrometeorite. The game is finding them.
These things are small, dust sized particles. But they have two important characteristics that aid in their discovery and identification;
- They are usually magnetic (although they can be glass) and
- They tend to be spherical,
Neither of these properties are exclusive to micrometeorites so a degree of close examination is required, and sometimes you have to resort to special means to confirm, involving Scanning Electron Microscopes.
So, how do you find the little beasties? Knowing where to look is useful. Any undisturbed flat space is good. Any flat Roofs of shops and factories. I haven’t had the bottle to approach any of these in Gosport so far, and there are a few.
You could start in the guttering of your conservatory, whilst the roof of your conservatory isn’t flat, and of course rain washes things, they can get trapped. One other important fact; it is averaged that one micrometeoroid per square metre per year. So there are a lot of them about. My next post on this topic will talk about the process of finding them and identifying them.