How many micrometeorites are falling in my garden?
Micrometorites are falling constantly everywhere. Their origin is unclear, according to some studies, most of them could come from comet dust. They are the oldest materials of the solar system. They are beautiful. They are everywhere. On your doorstep, on your home roof, on your car roof. Any step you take outdoor, you step on many of them. But you cannot see them. They are too small. A very good question is : How many are they? This apparently easy question is actually quite hard to answer. It depends on what you call a micrometeorite and what is your source of information. Next we are going to make an attempt answering. The first definition of micrometeorites was actually only referring to unmelted particles. But in the last 20 years it happens scientist are calling micrometeorites to both melted and unmelted particles. Let us consider as "micrometeorite" any particle less than 1 mm in diameter coming from the space "as it" (not from a bigger body t