Dust transports information about the composition of distant worlds over space and time. The matter can lie in our planetary neighborhood, like moon surfaces, or far away, like our galactic environment. The dust grains are like probes that give us the opportunity to analyse the material what these objects are made of.
Such kind of tools are of slightly different quality than known from optical astronomy. The classical way is to analyse radiation coming from the observed astronomical objects, but the dust instruments (so-called dust telescopes) get in physical contact with the alien material. When flown on a spacecraft, the dust telescope enables us to ``touch'' interstellar matter, moons, or the atmospheres of foreign worlds. Thus, Dust Astronomy opens up a new, supplemental window to investigate astrophysical and planetological questions.
The Helix nebula (NGC 7293) is a wreath placed by nature around a dying red giant. Nearing the end of its life the white dwarf in the centre of the nebula has blown off its outer atmosphere. The origin of the glowing dust disk around this star is still unclear. Interstellar dust was detected in our Solar System by in-situ dust sensors onboard the space missions Helios, Galileo, Ulysses and Cassini (Spitzer, AP/NASA)
Cosmic dust is a special component in space. It comprises particles that range from larger molecules with some thousands of atoms to small solid grains up to 10 micrometer in size. Cosmic dust links the microscopic world of atoms with the macroscopic world we sense around us.
