Tuesday, February 28, 2006

We're all headed for Sgr A*



Just to keep things in proper perspective....

"The Milky Way is a member of a collection of more than 50 galaxies called the Local Group. In terms of space occupied, Andromeda, or M31, is the biggest galaxy in this posse, but the Milky Way is the most massive."

"Astronomers estimate that the Milky Way contains about 100 billion stars. Recently, however, this number was upped by about a billion after the discovery that very old, nearly invisible stars had escaped earlier detections."

"Our sun, which is 4.6 billion years old, is located 26,000 light-years away from the galactic center on one of the spiral arms. It is a location considered more suitable than others for harboring life, in part because the central region is too chaotic, and in part because the concentration of metals there is too heavy, and it’s too light in the galaxy’s outer fringes."

"The sun makes one complete orbit around the galaxy about once every 225 million years."

"Colossal black holes are believed to lay at the heart of many galaxies, including our own. The Milky Way’s suspected black hole is called Sagittarius A*, or Sgr A*, and is thought to have between 3.2 million and 4 million times the mass of our sun."

"A black hole’s event horizon is a theoretical boundary beyond which gravity is so strong that no form of matter or energy can escape. But black holes are more than just indiscriminate and voracious gobblers of matter; they are forces of creation that help sculpt a galaxy’s shape and distribute its stars."

From "Scientists rewrite guide to Milky Way galaxy."

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