Dust is everywhere you look. It lands on your desk, on your shoes, and even in the air you breathe. Most people think dust is just dirt, but it can be much more.
Some dust is microscopic and can act as an allergen. When you sneeze, that tiny dust is often the cause. Other dust particles are so small they are called nanoparticles. These can travel deep into your lungs and make you feel sick. Not all dust is harmful. In rain forests, dust carries minerals that help trees do photosynthesis. The dust also helps create precipitation by acting as tiny seeds for water droplets in the atmosphere. A very small part of the dust we see is extraterrestrial. Scientists have found dust that is ancient, older than the Earth itself, drifting down from space. This ancient dust tells us about the early solar system. All this dust is part of the biosphere, the web of life that covers our planet, and it slowly breaks down through decomposition when it lands on the ground.
So the next time you see dust, remember it can make you sneeze, help a forest grow, or even be a piece of space history.
