We’re inside our galaxy, so it’s hard for us to get a good look at it. Also, all the interstellar dust and gas obscures our view along the plane of the galaxy, which makes it hard to see its exact shape. But modern instruments using radio waves have penetrated the haze, revealing many astounding features.

For one thing, the Milky Way is not the quiet galaxy we once imagined. Intense X-rays and plumes of gamma radiation blaze from its core, where stars whip around a central black hole at over 900 km/s. That’s fast enough to circle the Earth in 45 seconds.

Also, the Milky Way is consuming several of its smaller neighbour galaxies. In fact, we’re in mid-collision with one of them. The Sagittarius dwarf, a spherical galaxy, is currently embedded in the Milky Way’s disk, just 80 000 light-years from Earth, on the far side of the central bulge. Two nearby irregular galaxies, the Large and Small Magellanic clouds, are being gravitationally consumed as the Milky Way tears streamers of dust and gas away from them.
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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