Imagine the Universe!Ask an Astrophysicist This is the "Ask an Astrophysicist" service of the Imagine the Universe! web site. We are a small group of volunteers who work on space-based astronomical observations, including cosmic-ray, gamma-ray, and X-ray astrophysics. Our research subjects are often exotic, like black holes, dark matter, and the origin of the universe. We have already answered many questions, and have
