15. Earth is also covered with cosmic dust.
Earth is continuously being bombarded by comets and meteorites, most of which are relatively small and burn up in the atmosphere. Every single day, 100 tons of cosmic dust, most of it from these space rocks that disintegrate, descends on the Earth in the form of interplanetary fairy dust. NASA collects many of these particles for study. Why? Because they reveal much about what is going on in our solar system. Most of the particles fall safely to the ground, entirely unbeknownst to us. This dust is full of the minerals that compose much of the Earth’s surface, so we welcome it.
Most cosmic dust particles are minuscule, measuring between a few molecules and a few micrometers in size. Larger ones are called meteoroids, which is something we’re usually more familiar with. This cosmic dust, or space dust, can cause zodiacal light in the Solar System. This dust includes comet dust, asteroidal dust, and interstellar dust. They all contain complex organic compounds that can reveal necessary information about phenomena like the Solar System formation. The dust grains are irregularly shaped, with their porosity ranging from fuzzy to compact. It’s fun to think about fluffy cosmic dust.