cosmic dust 
noun [mass noun]
Small particles of matter distributed throughout space: glowing clouds of dense cosmic dust...
- There are many other potential sources of natural resources in the solar system, including cosmic dust, solar wind, and the atmospheres of gas giant planets.
- However, using Ulysses, they have now shown that, when the Sun's magnetic axis points near its equator, it allows much more cosmic dust to enter the Solar System than normal.
- The cosmic dust detector recorded two micrometeoroid showers in September and December.