What is stardust?

Quick explanation

Stardust, or cosmic dust is tiny particles — much smaller than dust mice — dispersed in the interstellare gas.

It can be annoying because it obscures observations, it can be exciting because it teaches a lot about the Universe, and it can be the seed of life.


The encyclopedia is being re-constructed; until I fix it, you'll have to

  1. do with this old and badly formatted version without nice pictures, or
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Why worry about dust?

Although dust sounds as the absolutely most boring subject with which you could concern yourself (next to banking, investment and insurance), it is in fact quite exciting, at least due to two features:

  • Dust grains may stick together and form pebbles, in turn forming rocks, asteroids, and planets, which are probably necessary to create life. And life is quite exciting.
  • Dust absorb and scatter light, severely affecting observations. In order to really understand what we observe, it is important to have at least some knowledge of the properties of the dust lying in the Universe between us and the object. Particularly in the very distant Universe, our knowledge on this limited. Since the very distant Universe also means the very early Universe, knowledge about how light travels through the dust and the gas can help us understand how e.g. galaxies were formed. And galaxies are also pretty exciting.