Instant Expert: What Interstellar Dust Can Tell Us
The Life of a Dust Grain koppillustration.comDust may help astronomers understand the formation of stars and planets Riding in a car through space, if you were to hang your white-gloved hand out the window, it would come back dirty. The space between the Milky Way's stars is filled with gas and dust-lots of dust. This summer, the European Space Agency's Planck satellite produced a high-resolution dust map. The ultimate goal of the project is to map the cosmic microwave background, the electromagnetic leftovers of the universe's violent beginning. Since warm dust grains emit microwaves, Planck made its map simply to see what's behind the dust. Cosmologists usually consider the dust-emitted microwaves to be "noise" that obscures their data, worth analyzing only to erase from their measurements of the cosmic microwave background. But for other astronomers, interstellar dust is useful in its own right. Some of them plan to use...