The Milky Way’s disk contains large clouds of interstellar dust and gas, which clump together into pinkish, star-forming regions. These, in turn, replenish the spiral arms with fresh groups of hot, young blue stars, known as open clusters. The disk’s bluish color comes from the young stars in the spiral arms. The Milky Way has hundreds of star-forming regions, and about 1 500 known open clusters.

Canadian Heritage Information Network
Australian Museums & Galleries Online, Australia; Centre of the Universe; Gemini Observatory, Hawaii; Glenbow Museum; The Manitoba Museum; National Research Council Canada; Planétarium de Montréal

© Canadian Heritage Information Network, 2003

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