Science Frontiers ONLINE No. 66: Nov-Dec 1989 | |
|
A spherical cloud of globular clusters surrounds the Milky Way galaxy. Each cluster is itself a spherical groups of stars. |
Many spiral galaxies, like our own Milky Way, spin ponderously in the center of a spherical cloud of scores, even hundreds, of globular clusters (see sketch). Not only do the globular clusters surrounding us display a different spatial distribution (spherical rather than flat-spiral), but their individual ages undercut galaxy theory. All of the Milky Way's globular clusters were supposed to have been formed when our galaxy was created. Yet, the ages of these clusters vary by as much as 5 billion years.
(Dayton, Leigh; "Globular Clusters Upset Theory of Galaxy," New Scientist, p. 34, May 13, 1989.)
Comment. We cannot resist mentioning still another cluster anomaly: The globular clusters do not participate in the galaxy's general rotation. Where did these oddballs come from?
Reference. The catalog volume: Stars, Galaxies, Cosmos, mentioned above, is described here.