Webcast: Black Holes, Thursday, at 7 pm PST -- by Curt Cutler, a Senior Research Scientist at JPL.

"Most normal galaxies contain, at their cores, black holes that are millions to billions of times more massive than our Sun. Most galaxies probably also contain millions of stellar-mass black holes, which are the remnants of massive stars. In this lecture I will try to explain what black holes are, in theory, and give a brief overview of some of their remarkable properties. I will then review some of what we know observationally about black holes in Nature. " Click here on Thursday at 7 p.m. PST for the webcast.