Cosmic dust is the key to the chemical evolution of stars, planets, and life itself, but its composition is not well understood, and we can’t currently collect samples for analysis. A few examples have arrived on Earth as interplanetary dust particles and comet dust, in meteorites, but their complicated history means they may not be representative.
Source:
https://phys.org/news/2020-01-simulated-cosmic-dustin-microwave.html